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
Used - Very Good: Logitech MX 5500 Revolution Black Cordless Cordless Desktop keyboard & Mouse Kit - Newegg.com
Logitech Unifying Receiver for Connecting Multiple Devices
Logitech Unifying Receiver for Connecting Multiple Devices
Logitech MX Revolution or Mx5500 USB Receiver Dongle Bluetooth C-uv35 for sale online | eBay