4G Home Anti Theft Alarm 2 Way Intercom PIR Motion Detection Wireless Video Doorbell for Villa Apartment Item Type: Wireless Video Intercom Doorbell Material: ABS Operating Current: <500mA Alarm Output: <80db within Approx. 1m / 3.28ft Wireless Frequency: 433Mhz, 2.4G, 125K Wireless Encoding: eV1527 GSM System: 850, 900, 1800, 1900MHz WIFI System: IEEE802.11b, g, n Wireless Standard Alarm Battery: 3.7V Lithium Battery x 1 (1000mAh) (Shipped with Built in Battery) Remote Control Battery: CR2025 x 1 (200mAh) (Shipped with Built in Battery) Main Door Sensor Battery: CR2025 x 1 (200mAh) (Shipped with Built in Battery) Operating Temperature: -10 to 55℃ Relative Humidity: <80% (Non condensing) Built in Voice Prompt Function, Supports 10 Common Country Languages (Chinese, English, German, Russian, Spanish, Polish, Italian, French, Portuguese, Greek)