✓ 4 Sensor and 1 Receiver- Receiver support to pair with multiple sensors, Sensors can be installed on different floors (rooms) to ensure that alert chime. ✓ Wireless Plug-in Receiver: The portable wireless plug-in receiver plugs into any standard outlet. The sensor uses 3 AAA batteries (Not Included). Detection time delay in between motion sensor alerts is configurable from 15 seconds to 30 seconds, just place the sensor at the entrance to your driveway and the receiver inside your home. ✓ Ideal for front doors, window frames, driveways, walking paths, and anywhere in your home you want to be alerted to motion. Also great to alert business owners that are working in the back, or out of sight, to customers entering their store.Please note that this not waterproof.Keep it away from rains or cover adequately. ✓ Easy, Fast, Wire Free Installation: Infrared sensor detects motion and sends a signal to the receiver. Chose from 38 Ringtones with Bright LED Light. Sensor is wall mountable. ✓ LONG RANGE CONNECTIION-Working Range up to 328 feet (100 meters) between receiver and transmitter allowing you to place it a good distance from the receiver to warn you of arrival and departure of family members, unwanted guests or solicitors, or anyone who visits your home or business.