Amazon.com: Logitech M570 Wireless Trackball Mouse – Ergonomic Design with Sculpted Right-Hand Shape, Compatible with Apple Mac / Microsoft, USB Unifying Receiver, Dark Gray (Discontinued by Manufacturer) : Electronics
Logitech Ergonomic Wireless Trackball Mouse, Easy Thumb Control, Smooth Tracking, Black - Walmart.com
Trackball - Wikipedia
What are the functions of the trackball in a computer? - Quora
Why did ball mice go obsolete? They seem superior to optical ones. a ball mice don't need a mouse pad, can work on any surface, and have good weight. Optical mice are