100% brand new and high quality.
Tracking systems: Optical.
Ultra-precise Scroll Wheel.
Optical technology works on most surfaces.
Ergonomically designed, long-term use without fatigue.
Intelligent connectivity, no need to code, plug & play.
Switch Life: 5 million cycle.
Size: 120(L) x 72(W) x 35(H)mm.
Weight: about 70g.
Compatible with Windows XP, Vista, Windows 7, ME, 2000 and Mac OS...or latest.