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
Logitech K400 Plus did not come with a USB dongle? Wait!! It's hidden in the box!! | THINKBOX
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
Replacement Unifying Receiver for Logitech Zone Touch Mouse T400 Ku | eBay
Lost Dongle of Wireless Mouse & Keyboard Logitech? (Different Replacement Logitech Usb Receiver) - YouTube
Logitech+Replacement+Bluetooth+USB+Receiver+for+diNovo+Edge+Mini+Mx5500+and+More for sale online | eBay