Note: This product is ecological chain brand product, there is no any marks on the products, please note it. The Self-Powered Wireless Doorbell can convert kinetic force into electric energy, no wire no battery required, remember your previous melody and volume level thanks to its smart memory function,support Home APP control, and smart linkage of other smart home devices (not included), suitable for home, offices and other areas. Features: - Self-powered electricity, pressing the button and force into electric energy. - No wire no battery required in transmitter, just plug and use with receiver. - 5-level sound volume adjustable, choose your favorite ringtone. - One transmitter can pair with many receivers with 36 of ringtone. - Smart chipset with memory function about the set ringtone storage after powering off. - The Doorbell Wi-Fi version support Home APP control, and smart devices linkage. - Durable flame retardant matte surface, simple and fashionable design. - Easy installation, no need complex steps, just sticking and start to use. (Wi-Fi Version)APP Connection: Step 1. 1.) Search and download the APP “ Home”on Google Play or App Store. 2.) Create a account then sign in your account. 3.) Click "+ Add device", "Devices nearby" to search the product, or manually enter the device name "Self-Powered Wireless Doorbell" and connecting. Step 2. 1.) Press the volume button for 10 seconds, until the yellow light flickers to reset WiFi 2.) Turn on the WiFi, BT, GPS on your smartphone and connecting with APP (If APP connection failed, please open the setting of the APP and switch the region to China, then reconnecting.) Specification: Brand: Product Name: Self-Powered Doorbell transmitter WifI: 2.4GHz Frequency: 433.92MHz Distance: about 50M outdoor Transmission frequency: 10dBm Operating force: about 700g Size: 67*67*19mm Weight: 43g Product Name: Self-Powered Doorbell receiver Host power supply: 110-240VAC Plug: US regulations Size: 68*68*31mm Weight: 74g Package size: 10 * 10 * 10cm / 3.94 * 3.94 * 3.94in Package weight: 350g / 13.38oz Note: 1.The Basic version can't connect to mobile phone, only simple doorbell function, not support Home APP. 2.Product size, product weight, and related specifications are theoretical values only. Actual measurements between individual products may vary. Package List: 1 * Doorbell transmitter 1 * Doorbell receiver 1 * Backplane 1 * Indicating sticker 2 * Expansion screw