If you purchase multiple Logitech products using the new Unifying USB receiver, you do not need to plug the second receiver into your computer. Instead, you can connect your new product to your existing Unifying USB receiver and store your new Unifying USB receiver for emergency use.
Most Logitech products that use the Unifying USB receiver have a storage compartment for the extra receiver. See the example below for a typical storage location on Logitech products:
NOTE: Not all Logitech products have storage for additional Unifying USB receivers. Check your product documentation to see if your product has a storage compartment for additional Unifying USB receivers.