Description: This wireless self-generating doorbell includes doorbell transmitter and receiver, with normal version and WiFi version, are a good helper in our daily life. Features: 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 Mixersion doorbell can interconnect with other intelligent Mixersion, WiFi Version; Product Name: Doorbell Transmitter Doorbell Receiver ; Specification:Size: 67*67*19mm (Diameter x Diameter x Height); Weight: 43g; Frequency: 433.92MHz; Distance: about 50M outdoor; Transmission Frequency: 10dBm; Operating force: about 700g Size: 68*68*31mm (Diameter x Diameter x Height); Weight: 74g; Host Power Supply: 110-240VAC; Host Plug: US Plug; 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. Q;A: 1. What’s the difference between transmitter and receiver? The wireless doorbell normally includes transmitter and receiver. The transmitter is also called the outdoor unit, the button to press and transmit to the receiver. The receiver is also known as the indoor unit, which is placed in the house and rings by receiving signals of outdoor unit. 2. Where and how is the transmitter installed? The transmitter can be installed on the wall beside the door or the glass doors instead of the metal doors (Anti-theft doors, iron doors and etc.) since the metal doors may interrupt the signal. We offer 3M double-sided tape and screws for you to choose from. You can refer to the above instructions and select the proper way. 3. What are the differences between the normal version and the WiFi version? The normal version is also called the No-WiFi version. It has the general function of the basic wireless doorbell, however, it can’t access to the Mixersion requires you to connect it with Mixer for example, when you have set all up with the WiFi versiion doorbell, if the rice has been ready, the doorbell would ring to remind you.