Brinno KNS100 Knocking Sensor for PHV1330 Hidden Front Door Camera

For use with the Brinno PHV1330 Hidden Front Door Camera. This sensor fits into a slot on the back of the Hidden Front Door Camera and triggers it to take a picture of anyone knocking at your door by sensing the vibration produced by knocking. Provides added security by allowing the Digital PeepHole Viewer to record photos of who's at your door even when you're not home. No batteries needed. Not for use with the optional Motion Sensor. Not compatible with the original Brinno PHV132512 Digital PeepHole Viewer.