This wireless motion detector from STI has a water-resistant constriction and is intended for outdoor use. If motion is detected in a monitored area the device sends a wireless radio signal to an indoor receiver, alerting users to a visitor or intruder. The detector is designed so that it doesn’t send an alarm if pets walk through the area. In the event that the supervised transmitter is removed, loses signal, or the battery is low, it will produce a beep.