Logitech Unifying Receiver for Connecting Multiple Devices
Logitech Mk700 Wireless Keyboard No Unifying USB Receiver Mouse Now Included for sale online | eBay
Amazon.com: Logitech New Unifying USB Receiver for Mouse Keyboard M515 M570 M600 N305 MK330 MK520 MK710 MK605 : Electronics
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