Wireless connection via Bluetooth® 4.0 LE or USB nano receiver TrackballWorks™ software lets you customize all 4 buttons, adjust cursor speed DiamondEye™ optical tracking technology for premium cursor control and accuracy Award-winning 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