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
How to pair more than one device with a Logitech receiver
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Unifying Receiver Wireless USB Dongle For Logitech PC Mouse keyboard 993-000439 | eBay