Logitech USB Wireless Receiver; P/N 810-000215, C-UAY59 T4 | eBay
Logitech C-UAY59 USB Receiver for V220 Wireless Travel Mouse w/Cradle 810-000272 | eBay
Logi Bolt USB Receiver for Multi-Computer / Device Use
Amazon.com: Logitech USB 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
Logitech Unifying Receiver for Connecting Multiple Devices