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: 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
Amazon.com: Logitech USB Unifying Receiver - 2 Pack For Personal Computer : Electronics
Original Genuine OEM Logitech logi USB Unifying Receiver Dongle Model C- U0007 | eBay
C-U0007 Unifying NANO USB Receiver Dongle For Logitech M215/505/705/905 K340/350 | eBay