This is a Wireless IR Motion Sensor Welcome Doorbell Door Bell-904A1. It can overcome any obstacles during the course of transmission and receiving. Installs quickly without the hassle of running any wires. It is advised to use it in the places where there is enough light￡? such as the office￡? home￡? shops￡? factories and other places￡? bringing the convenience￡? but also bring unexpected joy and a sense of security. Good choice for you!                                    Features            New and high quality<br>Made of high-quality material of aluminum<br>High sensitivity<br>Extend your home security system<br>Keeps you aware of intruders or visitors anywhere around your home<br>Suitable for home￡? office￡? unit￡? shop￡? warehouse￡? shed￡? garage etc<br>                                                            Specifications                        Power Supply          3 x 1.5v AA batteries (not included)        <br>          Three Settings          Music / Off / Voice        <br>          IR Distance          3 ~ 10 meters        <br>          Language Points          Chinese￡? English        <br>          Dimension          3.54" x 2.44" x 1.38" (L x W x H)        <br>          Material          Plastic        <br>                                                              Package Includes            1 x Wireless IR Motion Sensor Welcome Doorbell Door Bell-904A1<br>1 x Installation accessories<br>