Genuine HP Hewlett-Packard 5188-2466 PS/2 Optical Scroll Wheel Silver and Midnight Blue Ergonomic 3-Buttons Mouse Accurate Tracking Optical Design Model Number: M-SBF96 HP PS/2 Optical Scroll Wheel Mouse, Silver and midnight blue design PS/2 interface, 3-buttons, Scroll wheel acts as third button Optical design for smooth, accurate tracking on most flat surfaces Ergonomically designed Part Number: 5188-2466, Model Number: M-SBF96