Be notified that someone or something has come onto or into your property with a notification of a chime or louder alarm. Place the wireless IR motion sensor in a position to monitor up to range of 26 ft The sensor will send a wireless signal when motion is detected to the receiver up to 180 ft Away. The battery operated receiver can be installed on to a wall or can be kept portable for multi use. Batteries are included and the sensor is pre-learned to the receiver. Simply insert the batteries, chose the location that needs monitoring and security is ready. This product cannot be expanded. Only the one motion sensor included in this package can be used. No additional motion sensors can be added to this set. To create a multi motion sensor environment or if different types of sensors are desired please select the Ideal products SK632 and SK615. Up to 6 wireless sensors can be added to the SK632 receiver. For louder siren notification the SK626 can also be linked to an Ideal motion sensor SK615. This set is very useful for small businesses where staff must leave the main area, but still need to be notified of customers coming in.