LONG WIRELESS RANGE AND WATERPROOF:With a maximum operating range of 1,000 feet in open spaces, you 't miss any visitors even if you're in several rooms. The waterproof doorbell button works even in the harshest weather conditions like heavy rain, direct sunlight, and frost. EASY INSTALLATION:The easy-to-install button sticks well to any surface or use screws to secure the button to the door frame, just plug it in and you're to go. The receiver requires no batteries. The also flash blue light, so they can be seen even with headphones on. Scalable:Flexible design according to your actual needs. You can the number of transmitters and receivers according to your needs, and you can match freely. Whether in the bedroom or on the balcony, you 't miss a visit from outside your door. Not just as a doorbell:The can be used not only as a doorbell, also as a calling or warning system. Install it in a senior 's bedroom and push a button to alert others near the receiver that they may need attention. STAY SAFE: security cameras help you stay safe by seeing who's at your door without opening the door. Name: Lens:0309 480p 640*480 Battery Model:Standard 800mah Power Input:5v-2a Colour:Black Material:ABS Size:89x50x26mm Package Contents: 1 * Doorbell 1 * English manual Only the above package content, other products are not included. Note: Light reflection and different displays may cause the color of the item in the picture a little different from the real thing. The measurement allowed error is +/- 1-3cm.