Features: Bidirectional visual Intercoms: WIF Intelligents setting, long transmission, no need to open the door, can make video calls with visitors outside the door through mobile phones, reducing accidents caused by accidental entry. Video ringing tone: Internet Doorbells camera mobile phone video call cloud storage low power long standbys definition night Visioning. Battery usage: The Doorbells is equipped with 1000mAh rechargeable lithium battery. After being fully chargeds, it can be used continuously for 1 to 3 months. The ringtone is powered by USB and has long battery . for require security monitoring, such as homes, apartments, offices, especially for people who frequently visit such as couriers and visitors. It can be used to monitors areas such as entrances, garages, garden., providing security protections and convenient visitor management. At the same time, it can also serve as antitheft device, detecting abnormal situations and issuing warnings. Specifications: Material: Plastic Package Includes: 1Set Doorbells note: Please allow 0-1cm error due to manual measurement. please make sure you not mind before you bid. Due to difference between different monitors, the picture may not reflect the actual of the item.