Explain The Use And PrecautionsWireless doorbell is a smart doorbell that is different from traditional wireless doorbells. The transmission and reception can be freely learned and operated in pairing, and it is easy to use without electromagnetic interference. Product features:Stylish design, simple and convenient installation, simple design, a variety of music, optional 5-speed volumeRemote remote control receiving distance, straight line distance of 300 meters (workshop laboratory ), transmitter and receiver can be freely matched. Music settings:In the music, and hold the volume button for 4 seconds, the music indicator light is on, and the learning state is entered. At this time, the transmitter button to receive a flashing light and a ringtone, indicating that the pairing is successful. Freely match transmitter and receiver settings: and hold the volume for 4 seconds, the music indicator light is on, and the learning state is entered. At this time, the transmitter button to receive the flashing light and ringtone, indicating the configuration.Yes success Clear operation method: First and hold the receiver volume button without letting go, then plug into the socket and wait for the light to turn on for about 3 seconds, and then let go, that is, to clear all product connections. (you need to re-pair after clearing, operate carefully) Precautions: 1. Non-professionals should not open it without authorization and repair it by themselves to avoid damaging precision electronic components. 2. There is a high-voltage circuit inside, please do not open it for use. 3. The correct use of wooden products can effectively extend the service life. 4. The actual use of the remote control distance is shortened depending on the interference of environmental factors. 5. Please replace the battery if the use distance is significantly shortened or the sound is false. 6. Please do not install it on metal objects (such as iron doors, stainless steel doors, etc.) for installation. Receiver parameters: Voltage range: AC90-250V power consumption: 0.5W Receiving sensitivity: -110dbm operating frequency: 433.92MHz Transmitter parameters: Power consumption: 0.01mW Transmitter uses a 12V23A alkaline battery operating frequency: 433.92MHz Note: There is no effect of natural separation from the body, no electricity, metal, etc., and the actual use has a certain angle difference, which is the normal limit point. Plug Type:EU Plug,it applies to Indonesia, Germany, France, Spain, Italy and so on. Voltage:AC220V Color: Black Material: plastic Package Contents: 1 * Transmitter 2 * Receiver Only the above package content, other products are not included. Note: Light reflection and different displays may cause the color of the item in the picture a little different from the real thing. The measurement allowed error is +/- 1-3cm.