Product parameters: 1. Receiver working voltage: 110-240V 2. Transmitter working voltage: 4.5V (3 AAA batteries) 3. Receiver button: 1) Music: 38 pieces of music are optional, and the music logo button on the side can be adjusted 2) Volume: three levels of volume adjustment (high, medium, low) side volume sign button to adjust 3) You can set the sound and silent (sound: sound + indicator light silent: indicator light) 4. Working distance: up to 70 meters 5. Transmitter sensing distance: 3-7 meters 6. Receiver size: 76*80*33mm 7. Transmitter size: 80*59*45mm 8. Packing size: 17.5*11*7.5cm 9. Product gross weight: 0.22kg net weight: 0.14kg packing list: 1 X receiver 1 X transmitter 1 X manual Product operation instructions 1. Plug the receiver into the socket and power on, open the detector battery cover and insert the battery. 2. Put the rotating bracket into the back of the detector to jam 3. Push the detector switch to the ON position and wait for 10 seconds to enter the normal working state after self-checking time Precautions: 1. Try to avoid installing the sensor in a location directly facing the large air flow and close to the heat source. (Such as: cold air outlet, exhaust fan port, electric stove or nearby heating, etc.). Do not install the sensor directly in a place exposed to the sun and rain, or close to metal objects. 2. The sensor should be installed at a height of about 2 meters; the lateral detection of the sensor is more sensitive than linear (the human body directly faces the sensor), and it should generally be installed on the side or top of the entrance gate, and adjust the sensor to a suitable position through the mounting bracket In order to achieve the sensing effect 3. The interference between the sensor and the receiver should be reduced as much as possible. Generally, under the obstruction of a wall, the distance between the sensor and the receiver should be controlled at about 20 meters. 4. If the doorbell has a short receiving distance or malfunctions, please check the detector battery or replace it. 5. If the ambient temperature is too high (over 30 degrees), the sensing distance of the detector will be shortened, which is normal.