TheHigh Performance Indoor Motion Detector is highly sensitive to moving heat, utilizing its PIR (passive infrared detection) with a coverage area of 40’. This Indoor Motion Detector can easily be added to the tattletale security system at any time. The Pet Immunity feature allows for movement of pets up to 30lbs without creating a false alarm! Communicates with the High Performance tattletale base unit up to 1000' away. When used with our High Performance Wireless Signal Booster, add an additional up to 1000' per booster.