Amazon.com: Logitech Unifying Receiver USB Dongle for Logitech M185 Wireless Mouse and Keyboard : Electronics
Logitech latest Version Genuine Tiny Unifying General Receiver Dongle Connect up to Six Devices for Logitech mouse mice keyboard|unifying receiver dongle|logitech donglemouse dongle - AliExpress
Wireless Receiver Setup for Keyboard | Logitech Support