Citizen CL-S521. Maximum resolution: 203 DPI. Print technology: Direct thermal, Print speed: 150 mm/sec. Interface: USB 1.1, Serial, Fast Ethernet, Optional connectivity: Ethernet, Serial (RS-232), Connectivity technology: Wired. Compatible operating systems: Windows 7/XP/2003/2008/Vista. Maximum roll diameter: 125 mm, Media thickness: 0.0635 - 0.254 mm, Media thickness (imperial): 0.0635 - 0.254 mm (0.0025 - 0.01 ")