Features: Professional manufacturing, stable performance and good reliability. Made of premium ABS material, high quality and durable. Infrared sensor doorbell, strong sensitivity. The receiver volume can be adjusted, convenient in use. When the guest enters its detection range, the receiver automatically emits a pleasant music ringtone, and the red LED lights up. Specification: Condition: 100% Brand New Material: ABS Color: White Sensor operating voltage: DC 3V (2*AA batteries not included) Receiver operating voltage: DC 9V (1*9V laminated battery not included) Launch mode: 315 Emission distance: 100 meters (in an unobstructed, undisturbed environment) Infrared sensing distance: 3-7 meters Music Ringtones: Classic Single (to Alice) Packing: foreign trade neutral carton packaging Instructions for use 1. Gently push the front cover of the sensor up to install the battery. 2. Slide the battery back cover on the back of the receiver to install the battery. 3. Push the power switch on the side of the receiver up and open the receiver switch. 4. Install the sensor on the side of the entrance of the gate or where you need to detect where the human body passes. 5. Adjust the receiver volume, turn the receiver's power switch to the middle position to the low volume, and the top position to the high volume. 6. Adjust the sensor angle to the appropriate position. When the guest enters its detection range, the receiver automatically emits a pleasant music ringtone, and the red LED lights up. 7. Each time the sensor power is turned on, the wireless doorbell welcomer needs to perform the "self-test" function, about 10 seconds, and then enter the normal working state. Package List: 2 * Outdoor Units 1 * Indoor Unit 1 * Instruction Manual 4 * Plastic Brackets 1、Professional manufacturing, stable performance and good reliability. 2、Made of premium ABS material, high quality and durable. 3、Infrared sensor doorbell, strong sensitivity. 4、The receiver volume can be adjusted, convenient in use. 5、When the guest enters its detection range, the receiver automatically emits a pleasant music ringtone, and the red LED lights up.