The Ideal Security SK602 series wireless 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. Monitor driveways, gates, sheds, walkways, and swimming pools. 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.To scare off intruders, choose the high-decibel alarm. In situations where movement must be restricted, this alarm set can provide a gentle chime indication to warn others. 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 (390 feet). The sensors viewing angle covers an arc of 45 degrees and detects motion at a distance of 5-8 meters (16-26 feet).