Logitech MK520 Wireless Keyboard Mouse Combo with Unifying
User manual Logitech K800 Illuminated (English - 34 pages)
Amazon.com: Logitech USB Wireless Illuminated Keyboard K800 : Electronics
Replacement Unifying Receiver for Logitech Wireless Keyboard K340 Sh | eBay
For Logitech K800,K750,K710,K700,K520,K400,360 Unifying USB Dongle/Receiver 713929760527 | eBay
Amazon.com: SummitLink Unifying Receiver for Mouse and Keyboard Compatible for Any Logitech Product That Display The Unifying Logo (Orange Star, Connects up to 6 Devices) B083J7DYDT : Electronics