This product is an export product, the product contains a transmitter and receiver, the transmitter sets a card-like, you can put it in your wallet, key chain and keys together. When the key missing, simply press the keys on your card, key chain makes "Purring" sound, sound is easy to find the key. This product was accurate, distance, long battery life, good helper is careless

Working distance: outdoor 30-40 metres, indoor 15-25 meters, you can partition found

Operating frequency: 433.92MHZ