CST2545-5W(GL) (L-Trac Glow) USB Wired Ambidextrous High Performance Laser Ergonomic 5-Button Backlit Trackball (Black) - Made in the USA Width 3.75" (9.5cm), Length 6.75" (17.1cm), Height 1.75" (5cm) / Ball Size: 2.25" Three LED's illuminate the ball a vibrant blue Resolution: User selectable 400, 800, or 1600 counts per inch LED lights will automatically Turn Off after 5 minutes of inactivity. Buttons: 3 (programmable) + 2 switch jacks (programmable) which allows users to plug in two external buttons (Sold Seperatly - CST S-Button External Switch) for a maximum of 5 buttons