Easy, fast, cordless installation: Infrared sensors detect motion and send a signal to the receiver. Choose from 38 ringtones with bright LED lights. The sensor can be mounted on the wall. Wireless Receiver: The portable wireless receiver plugs into any standard outlet. The sensor runs on 3 AAA batteries (not included). The detection delay between motion detector alarms is configurable from 15 seconds to 30 seconds by simply placing the sensor at the entrance to your driveway and placing the receiver around your home. The operating range between the receiver and transmitter is up to 100 meters, allowing you to place it further away from the receiver to alert you of unwanted family members, guests or lawyers or anyone visiting your home or business arrival and departure of people. Use in entryways, window frames, walkways, walkways, and anywhere you want to receive motion alerts. Also great for alerting business owners working in the back or out of sight to customers entering the store. Note: Includes 2 plug-in receivers and 1 motion detector, requires 3 AAA batteries (not included). Receiver dimensions (L x W x H): 80 x 76 x 33 mm. Sensor size: 80 x 59 x 45mm