Detailed Product Description 2) 3 Buttons 3) 800DPI optical sensor technology for precise movement4) USB ,PS/2 and U+P Combo ports available 5) Key-Press Life: over 1,000,000 times 6) Can work on any surface except glass 7) Compatible with Windows95/98/NT/ME/2000/XP/Vista8) Fit for your left hand and right hand 9) Packaging : Blister, color box or white box