Professional 4-Inch Desktop Barcode Label Printer with Direct Thermal & Thermal Transfer Printing, 203 dpi, Up to 150 mm/s, USB, RS-232 and 360 m Ribbon Support

Brand: Citizen
Model: CL-S621II
MPN: CLS621IINEBXX
GTIN: 5060198390463

Product Overview

The Citizen CL-S621II CLS621IINEBXX is a professional 4-inch desktop barcode and label printer supporting both thermal transfer and direct thermal printing.

Designed for businesses that need flexible label production, the CL-S621II combines 203 dpi resolution, up to 150 mm/s printing, a maximum 104 mm print width, USB 2.0 and RS-232 connectivity with Citizen's durable Hi-Lift™ metal mechanism.

Unlike a direct-thermal-only printer, the CL-S621II can print using a thermal-transfer ribbon when longer-lasting labels are required, while retaining the option to print directly onto compatible heat-sensitive media without a ribbon.

Citizen's ARCP™ automatic ribbon tensioning and anti-wrinkle system helps maintain consistent thermal-transfer printing, while support for ribbons up to 360 metres reduces the frequency of ribbon changes.

The printer also incorporates Citizen Cross-Emulation™, providing automatic recognition of widely used printer command environments including Zebra® ZPL® and Datamax® emulation.

With a compact desktop footprint, internal power supply, large media capacity and front label exit, the CL-S621II is suitable for retail, logistics, warehousing, manufacturing, healthcare and general business labeling applications.

Professional Highlights

• Citizen CL-S621II desktop label printer
• Exact MPN: CLS621IINEBXX
• GTIN: 5060198390463
• 203 dpi / 8 dots per mm resolution
• Thermal transfer printing
• Direct thermal printing
• Maximum print speed up to 150 mm/s / 6 ips
• Maximum print width 104 mm / 4 inches
• Media width approximately 12.5–118 mm
• Large internal media capacity
• Supports ribbons up to 360 metres
• Inside- and outside-wound ribbon support
• USB 2.0 interface
• RS-232C serial interface
• Cross-Emulation™
• Zebra® ZPL® emulation support
• Datamax® emulation support
• Hi-Lift™ all-metal printing mechanism
• ARCP™ ribbon control technology
• Adjustable gap sensor
• Notch sensing
• Reflective black-mark sensing
• Front media exit
• Internal power supply
• Hi-Open™ case design
• Optional Ethernet interface
• Optional wireless LAN interface
• Optional parallel interface
• Optional cutter and peeler configurations where applicable

Exact Configuration - CLS621IINEBXX

This page is specifically for:

Citizen CL-S621II
MPN: CLS621IINEBXX
GTIN: 5060198390463

The documented standard interfaces for this configuration are:

• USB
• RS-232 Serial

Optional interfaces available within the CL-S621II platform should not be assumed to be installed in CLS621IINEBXX unless specifically confirmed.

If Ethernet, Wi-Fi or another interface is required, request configuration verification before ordering.

Thermal Transfer & Direct Thermal Printing

One of the principal advantages of the Citizen CL-S621II is its support for both major thermal label-printing methods.

Thermal Transfer

Thermal-transfer printing uses a ribbon between the printhead and label material.

Depending on the selected ribbon and media combination, it can be appropriate for:

• Product labels
• Inventory labels
• Asset identification
• Warehouse labels
• Manufacturing labels
• Longer-life barcode labels
• Applications requiring greater durability than ordinary direct thermal media

Ribbon and label material must be correctly matched to the application.

Direct Thermal

Direct thermal printing uses heat-sensitive label material and does not require a ribbon.

It is commonly used for:

• Shipping labels
• Courier labels
• Shorter-life barcode labels
• Dispatch labels
• Temporary inventory labels
• Other applications where direct thermal media provides sufficient service life

Having both technologies allows businesses to use the same printer platform for different labeling requirements.

203 dpi Print Resolution

The CL-S621II provides:

203 dpi / 8 dots per mm

resolution.

This is a widely used resolution for general barcode and business label production.

It is suitable for many:

• 1D barcodes
• 2D codes
• Product labels
• Shipping labels
• Warehouse labels
• Text
• Logos
• Graphics

For unusually small text, very small labels or high-density barcodes, a higher-resolution printer such as a suitable 300 dpi model may be preferable.

Up to 150 mm/s Printing

Citizen specifies a maximum printing speed of:

150 mm per second / 6 inches per second

for the CL-S621II platform.

Actual printing speed depends on printing mode, media, ribbon, print density, label design, interface and other operating conditions.

104 mm Maximum Print Width

The CL-S621II provides a maximum print width of:

104 mm / 4 inches

This makes it suitable for a broad range of 4-inch-class barcode and business labels.

The maximum media width is wider than the printable area, so media width and print width should not be treated as the same specification.

Media Width

Citizen specifies a media-width range of approximately:

12.5 mm to 118 mm

This provides flexibility for narrow labels as well as larger 4-inch-class applications.

Large Media Capacity

The CL-S621II is designed to accommodate large media rolls while retaining a desktop footprint.

Citizen specifies roll capacity up to approximately:

127 mm / 5 inches

depending on the media configuration.

This can reduce interruptions compared with printers designed around smaller internal label rolls.

Up to 360 m Thermal Transfer Ribbons

For thermal-transfer applications, the CL-S621II supports ribbons up to:

360 metres

The printer supports applicable:

• Inside-wound ribbons
• Outside-wound ribbons

This flexibility can help businesses select ribbon/media combinations according to the required label application.

Ribbon width, material and winding direction should still be verified before ordering consumables.

ARCP™ Ribbon Control Technology

Citizen equips the CL-S621II with its:

ARCP™ anti-wrinkle and automatic tensioning system

The system is designed to maintain appropriate ribbon tension during thermal-transfer printing and help reduce ribbon wrinkling.

This is particularly relevant for businesses using the printer regularly in thermal-transfer mode.

Hi-Lift™ Metal Mechanism

The CL-S621II uses Citizen's:

Hi-Lift™ all-metal print mechanism

The mechanism opens to provide access for loading media and thermal-transfer ribbon.

Its metal construction is designed for professional desktop printing environments requiring regular media changes and day-to-day operation.

Hi-Open™ Case

Citizen's Hi-Open™ case opens vertically rather than requiring significant additional space behind the printer.

This can be useful at:

• Packing stations
• Retail counters
• Warehouse desks
• Production workstations
• Compact labeling stations

where available workspace is limited.

Front Label Exit

Printed media exits from the front of the printer.

This helps keep the operating area compact and makes printed labels readily accessible to the operator.

Adjustable Media Sensors

The CL-S621II provides adjustable media sensing for:

• Label gaps
• Notches
• Reflective black marks

Correct sensor positioning and calibration are important when changing label dimensions or media types.

USB 2.0

The CLS621IINEBXX configuration provides:

USB 2.0 Full Speed

for connection to compatible host computers and business systems.

Software, operating-system and driver compatibility should be confirmed for the intended environment.

RS-232 Serial Interface

The printer also includes:

RS-232C Serial

connectivity.

Serial connectivity can be particularly valuable for:

• Existing POS systems
• Industrial computers
• Manufacturing systems
• Legacy business applications
• Equipment with established serial printer integration

The host system's serial configuration must match the printer settings.

Cross-Emulation™

Citizen's Cross-Emulation™ functionality is designed to simplify integration with existing label-printing environments.

The CL-S621II supports emulation environments including:

• Zebra® ZPL®
• Datamax®

This can make the printer relevant when replacing or integrating with applications originally configured around supported printer languages.

Compatibility should still be tested where the application relies on manufacturer-specific commands or unusual label templates.

Barcode Printing

The CL-S621II supports a broad selection of 1D barcode formats, including applicable:

• Code 39
• Code 93
• Code 128
• UPC-A
• UPC-E
• EAN-13
• EAN-8
• Interleaved 2 of 5
• Codabar
• GS1-related formats
• Other supported linear symbologies

The exact barcode should be tested at its intended dimensions where scanning performance is critical.

2D Barcode Support

The CL-S621II platform also supports 2D formats including:

• QR Code
• Data Matrix
• PDF417
• MaxiCode
• Aztec

This makes the printer suitable for label designs that require more than conventional linear barcodes.

The printer generates these symbols from the data supplied by the host application; it does not scan or validate them.

Internal Power Supply

The CL-S621II incorporates an:

Internal power supply

This helps reduce external power components around the workstation.

The appropriate regional power cable and package contents should still be confirmed for the exact unit being supplied.

Optional Ethernet

Ethernet connectivity is available as an optional interface within the CL-S621II platform.

It should not be assumed to be installed in the CLS621IINEBXX USB + RS-232 configuration.

If LAN/network printing is required, request the appropriate configuration before ordering.

Optional Wireless LAN

Wireless LAN is also available as an optional interface within the product platform.

Wi-Fi should not be assumed to be included with CLS621IINEBXX.

For wireless printing, confirm the required Citizen interface configuration and compatibility with the intended network environment.

Optional Cutter

An automatic cutter is available as an option for applicable CL-S621II configurations.

It should not be assumed to be included with CLS621IINEBXX unless explicitly stated in the quotation.

A cutter may be useful for:

• Continuous media
• Tickets
• Custom-length labels
• Applications requiring automatic separation

Optional Peeler

A peeling/label-dispensing configuration is also available for applicable applications.

This can help operators who repeatedly print and immediately apply individual labels.

Confirm the required factory or accessory configuration before ordering.

Retail Applications

The Citizen CL-S621II can support retail applications such as:

• Product labels
• Barcode labels
• Price labels
• Shelf-related labels
• Inventory identification
• Stockroom labels
• Goods-receiving labels

Logistics & Warehouse Applications

Potential logistics applications include:

• Shipping labels
• Dispatch labels
• Inventory labels
• Bin labels
• Carton labels
• Picking labels
• Packing labels
• Tracking labels
• Barcode identification

For very high-volume continuous warehouse printing, an industrial printer may be more appropriate than a desktop model.

Manufacturing Applications

Thermal-transfer capability makes the CL-S621II relevant to manufacturing applications where label durability is important.

Potential uses include:

• Work-in-progress labels
• Component labels
• Product identification
• Manufacturing barcodes
• Internal tracking labels
• Packaging identification

The correct ribbon and media combination should be selected according to the required durability and environment.

Healthcare & Pharmacy Applications

The CL-S621II may also be considered for appropriate healthcare and pharmacy labeling workflows.

Potential applications include:

• Internal inventory labels
• Product identification
• Pharmacy stock labels
• General barcode labels

Printer capability alone does not establish regulatory, clinical or pharmaceutical compliance. Required media, software, barcode standards and organizational procedures must be separately verified.

Technical Specifications

Brand: Citizen
Model: CL-S621II
MPN: CLS621IINEBXX
GTIN: 5060198390463
Product Type: Desktop Barcode Label Printer
Colour: Black

Printing

Printing Technology: Thermal Transfer + Direct Thermal
Resolution: 203 dpi / 8 dots per mm
Maximum Print Speed: Up to 150 mm/s / 6 ips
Maximum Print Width: 104 mm / 4 inches

Media

Media Width: Approximately 12.5–118 mm
Media Thickness: Approximately 63.5–254 μm
Maximum Internal Roll Diameter: Approximately 127 mm / 5 inches
Media Sensors: Adjustable gap, notch and reflective black-mark sensing

Ribbon

Maximum Ribbon Length: Up to 360 m
Ribbon Winding: Inside or outside wound, as applicable

Interfaces - CLS621IINEBXX

• USB 2.0
• RS-232C Serial

Optional Interfaces

Depending on configuration:

• Ethernet
• Wireless LAN
• Parallel

These optional interfaces should not be assumed to be installed in CLS621IINEBXX.

Printer Languages / Emulation

• Zebra® ZPL® emulation
• Datamax® emulation
• Citizen Cross-Emulation™ functionality

2D Codes

Supported formats include applicable:

• QR Code
• Data Matrix
• PDF417
• MaxiCode
• Aztec

Memory

Citizen documentation specifies:

16 MB RAM
4 MB Flash

Memory specifications should be considered part of the printer platform rather than general-purpose file storage.

Physical Dimensions

Approximately:

231 × 289 × 270 mm

Width × Depth × Height

Weight

Approximately:

4.5 kg

CL-S621II vs CL-S521II

The CL-S621II adds an important capability over the CL-S521II:

Thermal Transfer + Direct Thermal

The CL-S521II is positioned for direct thermal printing, while the CL-S621II adds thermal-transfer capability.

Choose the CL-S621II when ribbon-based printing and longer-lasting label options are required.

CL-S621II vs CL-S631II

A major distinction is print resolution.

CL-S621II

203 dpi

Suitable for general barcode, shipping, product and inventory labeling.

CL-S631II

300 dpi

May be more appropriate where the application requires:

• Smaller text
• Smaller barcodes
• Higher-density label layouts
• Finer graphics
• Greater detail

Higher resolution is not automatically better for every application. For ordinary 4-inch barcode labels, 203 dpi may be entirely appropriate.

Thermal Transfer vs Direct Thermal

Choose Thermal Transfer When

The application requires labels with greater durability or when using media designed for ribbon printing.

Typical considerations include:

• Longer label life
• Product identification
• Asset/inventory labels
• Manufacturing labels
• Specialized label materials

Choose Direct Thermal When

The application needs simpler, ribbon-free printing and the label does not require long-term durability.

Typical applications include:

• Shipping labels
• Courier labels
• Temporary inventory labels
• Short-life logistics labels

The application and media environment should determine the printing method.

Applications

The Citizen CL-S621II CLS621IINEBXX can be considered for:

• Barcode labels
• Product labels
• Shipping labels
• Courier labels
• Warehouse labels
• Inventory labels
• Manufacturing labels
• Retail labels
• Price labels
• Asset identification
• Dispatch labels
• Carton labels
• Receiving labels
• QR Code labels
• Data Matrix labels
• General business labeling

Purpose of Use

The CL-S621II is particularly suitable when a business needs a compact desktop printer combining:

• Direct thermal printing
• Thermal-transfer printing
• 203 dpi resolution
• 4-inch label capability
• USB connectivity
• RS-232 connectivity
• Long ribbon capacity
• Flexible media sensing
• Established barcode-printer emulation
• Professional desktop construction

Things to Verify Before Ordering

Please confirm:

• Exact MPN: CLS621IINEBXX
• Required quantity
• Label dimensions
• Direct thermal or thermal-transfer requirement
• Label material
• Ribbon requirement
• Ribbon type
• USB requirement
• RS-232 requirement
• Ethernet requirement, if any
• Wi-Fi requirement, if any
• Cutter requirement
• Peeler requirement
• Barcode format
• Required software/application
• Operating system
• Package contents
• Regional power cable
• Current availability
• Applicable UAE warranty

If replacing another barcode printer, provide the existing printer model and a sample label so compatibility can be reviewed before ordering.

Who Should Consider the CL-S621II?

The Citizen CL-S621II may be suitable for:

• Retailers
• Warehouses
• Logistics operations
• Manufacturers
• Distribution centres
• Stockrooms
• E-commerce operations
• Healthcare inventory environments
• Pharmacy stock applications
• Businesses requiring both direct thermal and thermal-transfer printing
• Businesses replacing compatible Zebra/Datamax-oriented workflows

Who May Need a Different Printer?

Consider another model if you require:

• 300 dpi or higher resolution
• 600 dpi printing
• RFID encoding
• Heavy industrial 24/7 printing
• Very high-volume continuous operation
• Media wider than approximately 118 mm
• Colour label printing
• Battery-powered mobile printing
• Ethernet already built into the exact supplied unit
• Specialized industrial environmental protection

The correct printer should be selected according to the actual media, print volume, connectivity and label-life requirement.

Compatibility

Compatibility depends on:

• Printer interface
• Operating system
• Driver
• Label software
• Printer language
• Label dimensions
• Media sensor configuration
• Ribbon and label combination
• Existing label templates

Cross-Emulation™ can simplify migration from supported printer environments, but it should not be interpreted as a guarantee that every command, label template or application will behave identically without testing.

How to Use

1. Place the printer on a stable indoor work surface.
2. Connect the appropriate regional power cable.
3. Open the Hi-Open™ case.
4. Load compatible label media.
5. If using thermal-transfer printing, install the appropriate ribbon.
6. Adjust the media guides and sensor position.
7. Close the print mechanism and printer cover.
8. Connect through USB or RS-232 as required.
9. Install the appropriate Citizen driver or configure the required printer emulation.
10. Set the correct label dimensions.
11. Calibrate the media where required.
12. Print a test label.
13. Check print position, darkness and barcode quality.
14. Verify the printed barcode with the actual scanning workflow before production deployment.

Why NEOTECH® UAE?

NEOTECH® focuses on matching professional label printers to the actual application rather than selecting solely from headline specifications.

• Exact Citizen MPN verification
• Direct thermal versus thermal-transfer guidance
• Label-size verification
• Ribbon and media guidance
• USB and RS-232 requirement checking
• Optional network-interface clarification
• 203 dpi versus 300 dpi guidance
• Barcode and 2D-code requirement checking
• Existing printer replacement guidance
• Transparent availability and lead-time communication
• UAE-focused quotation and delivery support
• No pressure to purchase when another configuration is more suitable

Learn First. Decide Second.

Request a Quote or Order in the UAE

Looking for the Citizen CL-S621II CLS621IINEBXX 203 dpi Thermal Transfer Label Printer?

For an accurate quotation, please provide:

• Quantity
• Label size
• Label material
• Direct thermal or thermal-transfer requirement
• Ribbon requirement
• USB or RS-232 requirement
• Network connectivity requirement, if any
• Cutter or peeler requirement
• Software/application
• Existing printer model, if replacing one
• Sample label, if available

For price, availability or a formal quotation:
Email: support@neotech.ae

Learn First. Decide Second.

Delivery - UAE

Delivery is available within the United Arab Emirates.

Order Cut-Off: 14:00 GST
Handling: 1–2 business days where applicable
Standard Transit: Approximately 3–5 business days after handling
Typical Total Delivery: Approximately 4–7 business days for confirmed available products

For non-stock or special-order configurations, delivery may extend to approximately 10–15 working days or up to 25 working days after payment/order confirmation, depending on supplier/manufacturer availability.

Current availability and the exact MPN/interface configuration should be confirmed before ordering.

FAQ - Citizen CL-S621II CLS621IINEBXX

Q: What is the Citizen CL-S621II CLS621IINEBXX?
A: It is a 203 dpi desktop barcode label printer supporting both thermal-transfer and direct-thermal printing, with USB and RS-232 interfaces in this configuration.

Q: What is the exact part number?
A: CLS621IINEBXX.

Q: What is the GTIN?
A: 5060198390463.

Q: Is the CL-S621II thermal transfer?
A: Yes. It supports thermal-transfer printing using compatible ribbon and media.

Q: Can it also print direct thermal labels?
A: Yes. The CL-S621II supports both direct thermal and thermal transfer.

Q: What is the print resolution?
A: 203 dpi / 8 dots per mm.

Q: What is the maximum print speed?
A: Citizen specifies up to approximately 150 mm/s or 6 inches per second.

Q: What is the maximum print width?
A: 104 mm / 4 inches.

Q: What media width does it support?
A: Citizen specifies approximately 12.5–118 mm.

Q: How long a ribbon can it use?
A: Up to approximately 360 metres.

Q: Can it use inside- and outside-wound ribbons?
A: Yes, the CL-S621II platform supports a wide range of ribbon configurations, including applicable inside- and outside-wound ribbons.

Q: Does CLS621IINEBXX have USB?
A: Yes. USB 2.0 is a standard interface for this configuration.

Q: Does CLS621IINEBXX have RS-232?
A: Yes.

Q: Does this exact configuration include Ethernet?
A: Ethernet is an optional interface within the CL-S621II platform and should not be assumed to be installed in CLS621IINEBXX.

Q: Does it have Wi-Fi?
A: Wireless LAN is available as an option within the product family but should not be assumed to be included with this exact configuration.

Q: Does it support Zebra ZPL?
A: Yes. Citizen documents Zebra ZPL emulation through its Cross-Emulation functionality.

Q: Does it support Datamax emulation?
A: Yes.

Q: Can it print QR Codes?
A: Yes.

Q: Can it print Data Matrix?
A: Yes.

Q: Can it print PDF417?
A: Yes.

Q: Does it have a cutter?
A: A cutter is available for applicable configurations, but it should not be assumed to be included with CLS621IINEBXX unless explicitly specified.

Q: Is 203 dpi enough for barcode labels?
A: 203 dpi is widely used for general barcode, shipping, inventory and product labels. Applications requiring unusually small text or high-density codes may benefit from a 300 dpi model.

Q: What is the difference between CL-S621II and CL-S631II?
A: The CL-S621II is a 203 dpi model, while the CL-S631II provides 300 dpi resolution. Selection should depend on label size, barcode density and required print detail.

Q: What should I verify before ordering?
A: Confirm the exact MPN, label dimensions, printing method, ribbon/media combination, interfaces, network requirement, cutter/peeler requirement, software compatibility, package contents, current availability and applicable UAE warranty.

Related Products

• Citizen CL-S521II Direct Thermal Label Printer
• Citizen CL-S631II 300 dpi Thermal Transfer Label Printer
• Citizen Desktop Barcode Label Printers
• 4-Inch Thermal Transfer Label Printers
• 203 dpi Barcode Label Printers
• USB & RS-232 Label Printers
• Thermal Transfer Ribbons
• Barcode Labels

Helpful Internal Links

• Citizen Label Printers UAE
• Barcode Label Printers UAE
• Thermal Transfer Printers UAE
• Direct Thermal Printers UAE
• 4-Inch Label Printers UAE
• Shipping Label Printers UAE
• Barcode Labels UAE
• Thermal Transfer Ribbons UAE
• Auto-ID Solutions UAE

Contact - NEOTECH® UAE

For Citizen CL-S621II configuration verification, media compatibility or quotation:

Email: support@neotech.ae
Address: Store 13, Computer Building, Al Fahidi, Bur Dubai, Dubai 44245, UAE

Disclaimer - NEOTECH® UAE

Citizen, CL-S621II, Cross-Emulation™, Hi-Lift™, Hi-Open™, ARCP™ and related names are trademarks or product identifiers of their respective owners.

This page specifically identifies MPN CLS621IINEBXX / GTIN 5060198390463 as a CL-S621II 203 dpi configuration with USB and RS-232 connectivity. Optional Ethernet, wireless LAN, parallel, cutter and peeler capabilities should not be assumed to be installed unless specifically confirmed for the unit being quoted.

Printer-language emulation can assist migration and integration but does not guarantee identical behaviour with every existing application, command or label template. Compatibility should be tested where business-critical.

Media, ribbon, software, operating-system compatibility, package contents, current availability and applicable UAE warranty should be confirmed before ordering.

Last Updated: 30 September 2026 (GST, UTC+4)