Logitech Unifying Receiver for Connecting Multiple Devices
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 - Walmart.com
Amazon.com: Logitech Unifying Receiver, 2.4 GHz Wireless Technology, USB Plug Compatible with all Logitech Unifying Devices like Wireless Mouse and Keyboard, PC / Mac / Laptop - Black : Electronics
Best Buy: Logitech Cordless Optical TrackMan Trackball Black/Gray 904369-0403