Intelligent CAT5 One Cable System Video Door Phone for Multi Apartment with Android/IOS APP for Remote Intercom and Door Release
1) Skybox is essential to be installed in every apartment for pushing their own visitor's video call to mobile app;Indoor monitor and audio handset is optional depending on whether you need to answer the call with a monitor in house or whether you prefer audio ONLY.
2)Second-confirm outdoor station, guard station and picture memory are optional
3) Indoor monitor and skybox are poweredfrom the Short Circuit Protector.
4) Multi-entrance connector is only needed if there are mutiple entrances for installing multiple outdoor stations in the same building.
5) Network connector is only needed if you want group management of the systems from two or more buildings with guard station.
6) The rest relative accessories in the list are necessary for the CAT5 one cable system.