Kensington TB550 Wireless Trackball Mouse, Thumb Operated, Rechargeable, Ergonomic Design (K72196WW), Black

Customers find the trackball mouse to be of top quality and appreciate its ergonomic design, noting it reduces hand pain and fatigue. The mouse connects easily to Mac devices and is comfortable to use. While the ball moves smoothly and is easy to set up, some customers report reliability issues with it stopping working within weeks. The scrolling functionality receives mixed feedback, with customers noting that it immidiately scrolls down.