Logitech MX Ergo Wireless Trackball Mouse

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 two computers, and copy-paste text, images, and files from one to the other using Logitech FLOW DUAL CONNECTIVITY?- Use with up to three Windows or Mac computers via included Unifying receiver or Bluetooth Smart wireless technology RECHARGABLE BATTERY?- Up to 70 days of power on a single charge; Number of buttons: 8 PRECISION SCROLL-WHEEL - Tilt and middle click wheel allows for precise scrolling and other convenient controls such as horizontal scrolling