Logitech K400 Usb Unifying Receiver - Wireless Dongle Receiver Usb Adapter 6 M905 - Aliexpress
Amazon.com: Logitech 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 K400r Wireless Keyboard With Touchpad & Unifying USB Receiver - Tested | eBay