Features: 1) USB mini wireless optical mouse with receiver inside 2) Accurate optical sensor up to 800dpi 3) High-precision optical sensor design, no mouse ball required 4) 256 ID codes, there is no interference even in case of many users 5) Auto power-saving sleeping function prolongs battery life 6) RF: 360 degrees, 1.5m radius 7) Suitable for notebook users 8) Dimensions: 85 x 51 x 30mm 9) Compatible with Windows 9X / ME / NT / 2000 / XP 10) Works on any surface except glass 11) Automatic sleep mode for energy saving