Description: Power Supply: 110/220V AC Backup Battery: 3.7V, 300mAh Lithium Battery (included) Consumption: Radio Frequency: 433Mhz WI-FI: IEEE802.11b/g/n APP: Tuya Selectable Melodies: 58 Volume Levels: 5 (includes mute) Sound Level(typical): 85dBA Expandable: up to 100 doorbell buttons/sensors and 10 remote tags Operation Temperature: -10-55 Doorbell Button Specifications: Power Supply: DC 3V 1* CR2032 Lithium Battery(included) Standby Current: Transmitting Distance: 100m/328ft (Without obstacles and no Interference) Radio Frequency: 433Mhz Item Size: 68*43*17mm / 2.7*1.7*0.7in Operation Temperature: -10-55 Specifications: Multifunctional Wireless Wi-Fi Doorbell - Not only the doorbell function, but also one key SOS help. DIY added 433MHz wireless devices to form the home anti-theft and accident alarm system. At the same time, it also has the alarm clock function, can set the alarm time remotely, which is used to remind the elderly to take medicine or the children to get up. All of these can be realized on the app. The app can also check the alarm record at any time Wi-Fi Real Time Alarm System - This Wi-Fi doorbell alarm is suitable for home, office, business, elderly living alone, nursing home, etc. Built in 58 melodies, you can distinguish which place triggers the bell through different melodies. You can also view it via the APP on your mobile phone or iPad. You can pair up to 100 wireless devices.You can choose them according to your needs. In the open space, the pairing distance can reach 328 feet. AI Low Battery Warning - Choose all the wireless accessories of our brand to connect with the Wi-Fi doorbell host. When the power of these accessories is low, you can receive the low battery warning on the app. So that you don't miss the alarm because the battery doesn't have electricity. Protect your home all day long. DIY Wi-Fi Home Security Doorbell Alarm - Best idea for your life, as long as your Wi-Fi network is wide enough, you can build a powerful protection and alarm system. Small doorbell big use, real DIY. Tuya APP can manage multiple WiFi doorbells. Share Wireless Alarm System with Your Family or Good Friend - There is no fee to share your alarm system to another one through our free app, So they also can be notified when the alarm is triggered. When the alarm is triggered by the elderly or children in the family, multiple people can receive the alarm notice at the same time. You can contact us if you have any problems in using our products, we will deal with them as soon as possible. Package Included: Doorbell*1 3M glue*1 User Manual*1