How to Pair Mouse & Keyboard with Logitech Unifying Receiver
Logitech Unifying Receiver for Connecting Multiple Devices
Logitech K540 Wireless Keyboard Only Very Good 5466 for sale online | eBay
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