2025 New Upgraded 4-Inch Printer: M421 label maker is a newly designed and upgraded 4-inch label printer for the Phomemo 2025, powered by a 2200mAh rechargeable battery. The small and slim design allows you to print labels anytime, anywhere and supports Bluetooth and USB connectivity for printing. Works with thermal labels ranging from 1.57 inches up to 4 inches/40 mm-106 mm Free and Multi-Functional App: Easily add images from your phone, tablet or laptop; customize your labels with over 1500 icons, 110 fonts, 200 templates and 20 languages with unlimited options on the "Print Master" app Cost-effective: Advanced thermal printing technology reduces consumable costs by eliminating the need for ink or toner; High-resolution 203 dpi print head ensures clearly readable labels - easy to scan and fast to read; Supports 40-106mm roll labels and folded labels Ultra Long Life Printer: Phomemo M421 Label Printer is suitable for 5V charging head. Built-in 2200mAh battery. Standby time of at least 2 weeks on a 2.5h charge. M421 4x6 printer is only 527g, making it compact and portable enough to print anywhere. The new auto sleep mode reduces power consumption by 25% and extends runtime by 2-3 hours. The labeler lasts up to 40% longer than comparable products on the market Easy to use: The Phomemo M421 4x6 shipping label printer is compatible with cell phones (Andrion, iOS), tablets, Windows (Windows 7/10/11), Mac OS, Chrome OS and Linux systems. Connect your smartphone or iPad to the Print Master app via Bluetooth. For connecting to a computer, simply download the drivers and the “Labelife” app and connect the device via USB to print shipping labels, barcodes, addresses, names, inventory labels and more Professional Brand : Phomemo is a thermal printer manufacturer over 15 years, offers lifetime free technical support; is available to assist you via online chat, email, remote-desktop, ensuring few minutes setup and easy operation. instruction videos are provided in the listing of image and Phomemo official website for better understanding