1. Receiver working voltage: 110-240V 2. Transmitter working voltage: 4.5V (3 AA batteries) 3. Button receiver: 1) Music: 38 pieces of music are optional, the music logo button on the side can be adjusted. 2) Volume: volume adjustment to three gears (high, medium, low) side volume logo button to adjust 3) Sound and silent can be adjusted (sound: sound + indicator light, silent: indicator light) 4. Working distance: up to 70 meters 5. Transmitter detection distance: 3-7 meters 6. Receiver size: 76*80*33mm 7. Transmitter size: 80*59*45mm Product instructions 1. Plug the receiver into the socket to power on, open the battery cover of the detector and insert the battery. 2. Place the rotating bracket on the back of the detector and get stuck 3. Push the switch of the detector to the ON position, wait 10 seconds for self-test time, then enter the normal working state Precautions: 1. Try to avoid installing the sensor in a position directly facing the large airflow and close to the heat source. (Such as: cold air outlet, exhaust fan, nearby electric furnace or heater, etc.). Do not install the sensor in direct sunlight and rain, or near metal objects. 2. The sensor should be installed at a height of about 2 meters, the horizontal detection of the sensor is more sensitive than the detection of a straight line (the human body directly faces the sensor). Generally, it should be installed on the side or at the top of the front door, and the sensor should be adjusted to a suitable position through the installation bracket. , in order to achieve the induction effect 3. The interference between obstacles and other wireless signals should be reduced as much as possible between the sensor and the receiver. Generally, under the obstruction of a wall, the distance between the sensor and the receiver should be controlled within about 20 meters . 4. If the doorbell has a short reception distance or malfunction, please check the battery of the detector or replace it. 5. If the ambient temperature is too high (more than 30 degrees), the detection distance of the detector will be shortened, which is a normal phenomenon. Packing list: 1 X receiver + 2 X transmitter