Logitech Ergo M575 Wireless Trackball Mouse – Graphite. 

Logitech ERGO M575 Wireless Trackball Mouse – Easy thumb control, precision and smooth tracking, ergonomic comfort design, for Windows, PC and Mac with Bluetooth and USB capabilities – Graphite

Ergonomic comfort design, relaxed hand and arm: The comfortable, sculpted ergonomic shape naturally fits your hand.Smooth thumb control, precise tracking: Great cursor control on any surface. Adjust the cursor speed with Logitech Options software.
Perfect for tight workspaces: Because the trackball doesn’t move, it’s perfect for tight workspaces and busy desks.2 ways to connect and multi-OS: Connect simply with Bluetooth or the USB receiver and never worry about drop-offs or lag up to a 33 ft (10m) range. Nominal value: 400 dpi
Plastic parts in ERGO M575 include post consumer recycled plastic (Graphite/Black: 50%, Off-White: 21%). Uses FSC-certified paper for responsible packaging.
Up to 24-month of use from a single AA battery with the USB receiver, you might just forget your trackball uses batteries at all.Convenient controls: Moving between documents or browsing your favorite websites is a breeze with large, easy-to-reach Back/Forward buttons and the precision scroll wheel.