Check the listing for details. Pack of 2 Logitech Wireless Unifying USB Receiver Dongle for Keyboard & Mice. Condition: Open box. Listed at 17.09 USD. Pack of two receivers. Items will come in bulk packaging. This item will work with all Logitech unifying devices that has a unifying logo (an orange star). If your device does not have the unifying logo, this receiver will not work. You can pair this unifying receiver with up to 6 of your unifying devices. You will need to download "Logitech Unifying Software" from Logitech website. The software is free. If you are using the receiver on a none-windows computer or device, you can first pair the receiver with your keyboard or mouse on a Windows PC, after successful pairing, you can then plug the receiver to any other devices and it will just work. Ships from USA via USPS First Class mail within 1 business day.