Trust Optical Combi Mouse MI-2500X. Device interface: USB+PS/2, Movement detection technology: Optical, Movement resolution: 800 DPI. Bundled software: CD-ROM with software. Minimum processor: Pentium CPU, Minimum hard disk space: 10 MB, Minimum RAM: 64 MB. Mouse dimensions (WxDxH): 129 x 67 x 41 mm. Compatible operating systems: Windows 98, ME, 2000, XP