Amazon.com: Logitech New Unifying USB Receiver for Mouse Keyboard M515 M570 M600 N305 MK330 MK520 MK710 MK605 : Electronics
Logitech MK520 Complete Wireless Combo K520 Keyboard and M510 Mouse USB Unifying (920-008972) (Renewed) (920-008972-cr) Keyboards - Newegg.com
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
Amazon.com: Logitech MK520 Wireless Keyboard and Mouse Combo — Keyboard and Mouse, Long Battery Life, Secure 2.4GHz Connectivity : Electronics
Logitech K520 Wireless Keyboard Unifying (NO USB RECEIVER) 97855066718 | eBay
Amazon.com: Logitech Unifying Receiver USB Dongle for Logitech M185 Wireless Mouse and Keyboard : Electronics
Logitech Unifying Receiver for Connecting Multiple Devices