This is a receiver compatible with Logitech Bolt products. It's a very convenient multi-point device that supports up to 5 devices with a single receiver. It's recommended to keep one on hand for frequently used devices. Having 2-3 won't be a problem. Some products don't come with a receiver, so you'll have to buy one separately (such as with inexpensive keyboards and mice). It's recognized in the same way as a wired connection, so it's characterized by its very fast startup.