HP Optical PS/2 Mouse GM278AA#ABA M-SBQ133 (5188-6230) Optical Sendor. Smooth &amp; Accurate. Three Buttons. PS/2 Connect. INSTANT SETUP: PS/2 Connectivity for easy use. No Driver Required. Mantenance Free: Optical sensor replaces mouse ball. No more mouse ball cleaning or mouse pad. Smooth and accurate cursor movement all the time. System Requirements: Available PS/2 Port. Compatible with Microsoft, Windows, XP/Vista.