How to Pair Logitech Mouse /Keyboard with Unifying Receiver - YouTube
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
Wireless Receiver Setup for Keyboard | Logitech Support
Connect multiple Logitech wireless devices using same USB receiver
Logitech MK520 Wireless Keyboard Mouse Combo with Unifying