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
Wireless Dongle Receiver Unifying USB Adapter for logitech Mouse Keyboard Connect 6 Device for MX M905 M510 Keyboard K400|Wireless Adapter| - AliExpress