Logitech Unifying Receiver for Connecting Multiple Devices
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
Dongle USB Receiver Logitech K520 Keyboard | eBay
Logitech MK520 Wireless Keyboard Mouse Combo with Unifying
Amazon.com: Logitech USB Unifying Receiver - 2 Pack : Electronics
For Logitech Unifying Wireless Solar Keyboard K750 K800 K520 Dongle USB Receiver | eBay