Mouse Included: Built-in trackball Tracking Method: TrackBall Buttons: 3 Normal Keys: 81 Function Keys: 14 Distance: 33 ft. Operating System Supported: Windows 7 (32-/64-bit) / Vista (32-/64-bit) / XP (32-/64-bit) / Server 2003 & 2008 (32-/64-bit) / 2000 SP4 Dimensions: 13.6" (L) x 6.4" (W) x 1.9" (H)