This is a electrical personal reminder device. It comes with a transmitter and a receiver, both are battery operated. The transmitter will be attached to the item you want to secure: bag, lagguage, wallet, etc. And the receiver which has the size of a regular keychan will be with the owner. The range can be adjusted from 0-20m. once the item with the transmitter is out of the set range, the alarm on the receiver will be on to warn the owner the item is stolen or the owner forgot to take his item.