Model Number: WH-E34-USB Interface 5V,3A Brand Name: WH,Brightek Key Specifications/Special Features: Printing method: direct thermal line printingPaper width: 57mmPrint width: 48mmFor more info, please refer to the table below ItemsSpecifications Printing method Direct thermal line printing Paper width 57mm Print width 48mm Resolution ratio 8 dots/mm (384 dots/line) Life of print head 50km Printing speed 20mm/sec (when power supply is 5V) character size 9x17 dots, or 12x24 dots Chinese character library GB2312, 16x16 dots, 24x24 dots Paper supplied Thermal roll paper (57mm wide, 30mm) Interface USB/Serial RS232/TTL/485 interface Input Power DC 5V, 3A/9-24V 25W Operating temperature 0 - 50°C Storage temperature -20 - 60°C Operating humidity 20 - 85% Storage humidity 5 - 95%