Kensington Pro Fit™ USB/PS2 Wired Mid-Size Mouse idea: A mid-sized mouse for full comfort. Comfort and reliability are critical in any office environment. And the Kensington Pro Fit™ USB/PS2 Wired Mid-Size Mouse delivers both. The mid-sized right-handed design feels great in the hand while the wired plug-and-play connectivity delivers high reliability and zero setup. Features Mid-size, right-handed design for lasting comfort Dedicated forward and back buttons Designed to withstand drops and spills USB/PS2 connection delivers instant plug and play use Specifications Plug and play No software required Compatible with Windows® 7, Windows Vista®, Windows® XP Dimensions 4.25"L X 1.5"H X 2.75"W