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
Logitech USB Unifying Receiver, Black | OfficeSupply.com
LANGTU USB 2.4 GHz Wireless Technology Unifying Receiver – LANGTU Store