eBay

Ergonomic sculpted design - unique adjustable hinge allows you to customize the trackball angle from 0 to 20 degrees for a more natural, comfortable hand position, and reduced muscle strain
Cross-computer control- game-changing capacity to navigate seamlessly on 2 computers, and copy-paste text, images, and files from one to the other using Logitech flow
Dual connectivity- use with up to 3 Windows or Mac computers via included Unifying receiver or Bluetooth smart wireless technology
Rechargeable battery- up to 70 days of power on a single charge; Nominal value : 380 dpi
Precision scroll-wheel - tilt and middle click wheel allows for precise scrolling and other Convenient controls such as horizontal scrolling
Minimal and maximal value: 512-2048 dpi