Description:Wireless door chime is great for retail store， shops， business， salons， front / back / side door， etc.Attach this infrared alarm anywhere you want and instantly know when someone crosses the beam.Good quality and 100% brand new.Infrared sensor detects motion and sends a signal to the receiver.Wireless installation， just place the sensor at the entrance.Receiver requires 2x AA batteries， transmitter requires 1x 9V battery (batteries not included)Send audible chime sound， alerting you that somebody is approaching (Note: only one music type sound， no changing )Working Range: Up to 100 meters / 328 feet between receiver and transmitterTransmitter Size (L x W x H): Approx. 3.5 x 2.4 x 1.8 inchReceiver Size (L x W x H): Approx. 3.5 x 2.6 x 1 inchReceiver Switch Setting: High / low volume / offMaterial: PlasticColor: WhitePackage included:1x Transmitter1x Receiver2x Mounting Bracelets1x Manual