infra red infrared beam entry alert door chime works with door open

infra red infrared beam entry alert door chime works with door open The LD-40 passive infrared door announcer is a self-contained, battery operated, motion detector. From the detector comes a pleasant sounding chime every time someone enters its detection area. This stand alone unit detects infrared energy emitted by the human body while in motion. It is unaffected by sunlight, car headlights, reflections, shadows or colors. It operates with a door opened or closed. Designed with state-of-the-art electronic components to operate under the most demanding circumstances the LD-40 is ideal for monitoring small office and shop entrances.

* Powered by 9 volt battery
* Long battery life circuit design
* Fully automatic, no alignment required
* Ceiling, above door, or side mounting
* No wires, easy installation
* Welcomes with a pleasant chime
* Prevents unannounced entry
* Helps control theft
* One year warranty
* Low Cost