Wireless connection via Bluetooth LE or USB nano receiver. KensingtonWorks software lets you customize all 4 buttons, adjust cursor speed. ChromeOS user can get HID functions for a trackball but will not be able to customize their device through KensingtonWorks. DiamondEye optical tracking technology for premium cursor control and accuracy. Patented Scroll Ring lets you scan up and down pages with ease. Large ball is designed as a perfect sphere to provide exceptional precision. Detachable wrist rest supports hand and wrist for ergonomic comfort. Ambidextrous design works equally well for both right-handed and left-handed users. Auto-sleep helps conserve AA battery life. 2.4 GHz, Bluetooth 5.0. Black.