FY-0256 2 in 1 PIR Infrared Sensors Wireless Doorbell Alarm Detector for Home Office Shop Factory, EU Plug Features 1. Adopts infrared detect technology. 2. No wiring design makes it simple to use and easy to install. 3. Long sensing distance. 4. 38 songs for choice in total, you can choose the song throgh click the music key on the side of receiver. 5. 3 levels of volume for adjust, you can adjust it by click the volume key on the side of receiver. 6. The receiver has the function to set voiced noiseless modes, you need to adjust it by click the volume key on the side of receiver. 7. It is functional for home, office, or commercial buildings. 8. The transmitter is powered by 3 AA batteries, the baterries are not included in this item. 9. Please install it refer to the tips described on the EnghlishChinese manual. How to use 1. Open the sensor cover, install 1 x 9V battery, then opens the switch in circuit board 2. Open the receiver cover and you can install 2 x AA batteries 3. Push the switch on the side of receiver to open the switch 4. Install the sensor on the both of door side or other some places you want to detect human body passed by 5. Adjust the receiver tone volume, the power switch to the mid-position is low-volume, high-volume on uppermost position 6. Adjust the angle of the sensor to a suitable position, when the guest enters its detection range, the receiver automatically sends sweet music ringtones, the red LED lights 7. When you open the sensor power, wireless doorbell is required for each SELF-TEST function, about 10 seconds, and then enter the normal working condition.