Feature: 1. MULTI FUNCTIONAL: No need for WIFI connection, just pair and use. Safe information transmission, supporting video intercom, photo and video recording, 80° wide angle, maximum 128G memory card. 2. EXTERNAL ANTENNA DESIGN: Long distance and anti interference, industrial grade external antenna, transfer distance up to 150m in open space, 50m indoor (through 1 wall). 3. HIGH DEFINITION 4 INCH SCREEN: Utilizes high definition large screen and camera. Multiple music ring tones to choose from, adjustable ring tone volume. Capturing outsiders instantly with one click photo and video recording function. 4. MULTI LANGUAGE SUPPORT: Supports English, Simplified Chinese, Traditional Chinese, Japanese, German French, Russian, Italian and 12 languages in total, bring you professional use 5. 2 INSTALLATION METHODS: You can use double sided tape or screws to drill holes for mounting according to actual needs. The installation process is simple and convenient. Specification: Item Type: Video Doorbell Display Screen: 4 inch TFT Color Screen Intercom: Duplex Intercom Display Battery: 3.7V 2000MAH Polymer Battery x 1 (Built in Battery Included for Display Screen) Outdoor Unit Battery: 3.7V 5000MAH Polymer Battery x 1 (Built in Battery Included for Outdoor Unit) Memory Card: Supports up to 128G memory (Memory card format is FAT32) (Memory Card Not Included) Supports: Motion Detection (PIR), Night Vision: 940nm Infrared Light (No Red Exposure) Supports: Active Wake up for Indoor Host Screen, Detection of Bright Screen (Alarming Display Screen Automatically Lights up) Language: English, Simplified Chinese, Traditional Chinese, Japanese, German, French, Russian, Italian and 12 other languages Charging Interface: Type C Operating Temperature: 10%-80%. Package List: 1 x Display Screen 1 x Outdoor Unit 1 x Mounting Bracket 4 x Installation Screws 4 x Expansion Tubes 1 x Sealing Gasket 1 x Double Sided Tape 1 x USB C Data Cable 1 x User Manual