The Ideal Security SK602 wireless expandable motion sensor alarm and alert uses a motion sensor to detect motion and sends a wireless signal to the linked receiver. Once a signal is received by the receiver, the unit will chime, alarm (100dB) or just flash lights. The battery powered motion sensors can be used to monitor driveways, gates, sheds, walkways, swimming pools, and more. Ideal Security’s SK602 motion sensor alarm can also be used to monitor front or back doors at small businesses, or supervise children to keep them safe. The motion sensor works in both light and darkness, but it is not pet-immune. The receiver has an on and off switch and volume control for the alarm and chime. To deter intruders, choose the high-decibel alarm setting. In situations where movement must be restricted, such as deterring children away from balcony or patio doors, this alarm set can provide a gentle chime indication to warn guardians. Use the lights-only mode to silently keep an eye on movement in areas of your home, shop, or place of work. The range from the sensor to the receiver is up to 120 meters (395 feet). The sensor’s viewing angle covers an arc of 45 degrees and detects motion at a distance of 5-8 meters (16-26 feet). Up to 50 sensors can be linked to the alarm. Additional sensors are available and sold separately (SK602-1G). The motion sensor unit can be installed indoors or outdoors. When installing outdoors, try to shelter it from direct rain and sun exposure. The alarm unit is designed for indoor applications only. Both units can be fastened to the wall using the screw keyholes on the back, or they can be kept as portable units. Three AAA batteries are required for the sensor (not included); to use the alarm unit wirelessly, three C batteries are required. Ideal Security has been supplying quality hardware since 1956. Please explore our other security and protection products for your home.Charcoal grey models have blue LEDs, white models have red LEDs. Motion sensor unit can be used outdoors. Low battery indicator. Batteries are not included: 3 C batteries for the receiver and 3 AAA batteries for the sensor. Transmission range of up to 390 feet between motion sensor and alarm unit. Senses motion over a 45 degree arc, up to 26 feet away. 4 alert settings: Loud alarm, Loud chime, Soft chime, Lights only, alarm sound same for all additional sensors. Add additional sensors: Up to 50 sensors can be linked to the receiver((SK602-1G(Grey) SK602-1(White)). Starter package includes 1 PIR motion sensor unit, 1 receiver / alarm unit and a charging cord.