Someone knocking at the door? You’ll know right
away with the Knock Sensor. It easily attaches with
velcro to the inside of your door to let you know when
you have visitors! Since it is sensitive to vibrations
only, it will not pick up other outside noise. When
activated, a bright, flashing light alerts you.
- Easy installation
- Optional bracket to hang on door
- Automatic shut-off after five seconds until activated again
- 9V battery (not included)