The Used Kensington Expert Mouse Trackball Model #64215 Ver 5.0 is a white trackball mouse designed for PC and IBM PS2 compatibility. With a maximum DPI of 1000 and optical tracking method, this trackball offers precise navigation. It features programmable buttons, ergonomic design, and 4-way scrolling for enhanced usability. The wired connectivity via PS/2 and serial options ensures reliable performance for your computer system. With its compact unit quantity of 1, this trackball mouse is a dependable choice for those looking for a reliable and efficient pointing device.