Logitech Unifying Receiver for Connecting Multiple Devices
Logitech K400 Black Wireless Keyboard with Built-In Touchpad & USB Receiver | eBay
K400r Black Wireless Touch Keyboard (UK Layout)
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