SOLVED: USB for wireless Logitech keyboard lost. - Logitech Harmony Smart Keyboard - iFixit
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 K400 Plus did not come with a USB dongle? Wait!! It's hidden in the box!! | THINKBOX
Genuine Logitech Unifying Mirco Dongle Receiver USB For keyboard K400r K400plus | eBay
Genuine Logitech Unifying Mirco Dongle Receiver USB For keyboard K400r K400plus | eBay
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
Short review: Logitech K400r vs Plexgear Mediatrack Ergo - Erik Moberg's personal homepage - photography, gadgets, DIY, and more
Wireless Usb Receiver Dongle 6 Channels Adapter For Logitech Unifying Keyboard K400/mouse Mx M905 M510 Repair Replacement - Instrument Parts & Accessories - AliExpress
Logitech K400 Plus Touchpad Keyboard for TV connected PC