Description:This Xiaomi Linptech wireless self-generating doorbell includes doorbell transmitter and receiver, with normal version and WiFi version, are a good helper in our daily life.Specification:Brand: Linptech (Xiaomi Ecological Chain)Color: WhiteType: Normal Version, WiFi VersionProduct Name: Self-generating Doorbell TransmitterSize: 67*67*19mm (Diameter x Diameter x Height)Weight: 43gFrequency: 433.92MHzDistance: about 50M outdoorTransmission Frequency: 10dBmOperating force: about 700gProduct Name: Self-generating Doorbell Receiver Size: 68*68*31mm (Diameter x Diameter x Height)Weight: 74gHost Power Supply: 110-240VACHost Plug: US RegulationsFeatures:1. Exquisite appearance. Made of Polycarbonate, durable and non-toxic material.2. No battery required. The doorbell rings as soon as you press it lightly since it generates electricity with motor instead of batteries.3. Easy to install and convenient to use. The transmitter and receiver are self-matched as soon as you unpack it. There are no wires and batteries required for transmitter. 4. Adjustable music and volume. Five levels volume and 36 pieces of songs, the receiver can choose the music at will.5. Different doors with different music.Different doors, different bells. You can distinguish the front door from the back door since the receiver has 36 pieces of songs to choose from, and each piece of song can correspond to a single transmitter.6. Free combination. Transmitters and receivers support flexible matching.7. Power off memory with intelligent chip. It can keep the music set before with intelligent memory storage.8. Interconnecting with other Mijia Devices.WiFi version doorbell can interconnect with other intelligent Mijia devices, controlled by Mijia APP or Xiao Ai.Instructions:Install on the clean and flat wall:1. Tear off the double-sided tape on the back of the door bell transmitter.2. Stick it on the wall after tearing off the double-sided tape. Install on the dirty and rough wall: 1. Fix the back plate on the wall with a screw.2. Tear off the double-sided tape on the back of the door bell transmitter.3. Stick it on the wall after tearing off the double-sided tape.Package Included:1 x Doorbell Transmitter1 x Doorbell Receiver1 x Backplane1 x Instructions1 x Indicator2 x Expansion Screws