The Safe Family Life Key Finder has many uses. It can be used to keep track of your keys, wallet, or any item you misplace on a regular basis. The Remote Key Finder is very convenient and easy to use. For example just attach it to a set of keys and when you need to find them press one of the buttons on the small credit card style transmitter and the Safe Family Life Key Finder will sound a beeping alarm for 4 seconds. The Key Finder will detect the signal from up to 50 feet away even if it is hidden under pillows or in another the room. The radio frequency penetrates walls, cushions, leather, and sofa pillows. Never lose your keys, wallet, or remote control again. It uses a 433 MHz frequency and has a sound of 90dB. Remote distance range: 50 feet. It comes with 1 small credit card style remote transmitter and 2 key fob receivers. The receiver uses a CR2032 and is included. The transmitter uses 2 CR2016 and they are included. Batteries can last up to a year depending on use, it is good to test each key fob weekly.