Wireless USB Receiver Dongle 6 Channels Adapter For Logitech Unifying Keyboard K400/Mouse MX M905 M510 Repair Replacement - AliExpress
Logitech Unifying Receiver for Connecting Multiple Devices
Logitech Unifying receiver - Wikipedia
Logitech K400 Plus Touchpad Keyboard for TV connected PC
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 K400 Plus keyboard RF Wireless Y-R0055 NO DONGLE NOP BATTRIES 754292140295 | eBay
Logitech Wireless Touch Keyboard K400 Plus (920-007119)