Westgear M-250 USB Portable Mouse - Blue (120-1095) The Westgear M-250 USB Portable Mouse encompasses an ergonomic design with sculptured side panels that conform to your fingers. 800/1000/1600 Adjustable Function Front/Back Button Function Enhanced Optical Sensor Metallic Color Accents 4 foot USB Cable Product Dimensions: 2.4-inch L x 1.3-inch W x 3.9-inch H Easy to install, no software required