Specifications: Interface: PS/2;USB;USB+PS/2 Resolution:400/800 CPI Mouse Buttons: free key+ 1 Wheel Micro Switch:1 million cycle life Encoder: Opto-Mechanical Browse way: Vertical + Horizontal Scroll Driver compatible with: Windows 98/2000/ME/NT/XP Product size: 104.36(L)59.7(W)35.4(H) mm Approval: CE;FCC