All-in-one touch screen: You can connect the screen to an EZVIZ doorbell like HP3/DB2/CP3/EP3X/CP7 via WiFi and then manage your door intercom system. For example, you can respond to visitors and open/close door. When a visitor knocks on the door, you know who is outside. Wireless installation: This smart 7-inch color screen is 100% wireless and has a rechargeable 4600mAh lithium battery. You can connect the screen to other EZVIZ devices via 2.4GHz WiFi. Up to 30 EZVIZ devices: This SD7 display supports access to doorbells, peepholes, cameras, DIY locks and other devices. More than 10 SD7 screens can be connected together and up to 30 other devices can be connected to SD7 at the same time. Versatile mounting methods: It can be mounted on a wall or placed on a table with the included stand, or you can just bring the screen with you to avoid missing important images. Access EZVIZ App: Add your smart SD7 screen to EZVIZ App to manage and control your screen and other devices anytime and anywhere. For example, you can view real-time monitoring via the APP.