1. Material: ABS, electronic components 2. Features: long transmission distance, built-in 52 music ringtones, 5-level volume adjustment, LED indicator light, strong penetrating ability 3. Applicable range: 300 meters 4. Music: 52 pieces of music 5. Volume: 5 levels of volume 6. Power supply mode: power supply 7. Receiver battery: plug directly into the power supply 8. Transmitter battery: 12V 23A battery x 1 (delivery without battery) 9. Installation method: double-sided tape fixed / screw fixed 10. Waterproof grade: IP44 11. The receiver has an indicator light, and the bell light is on 12. Strong penetrating ability to meet household needs 13. The AB door function can be set to distinguish the signals from different sensors and set different sounds 14. The waterproof design of the transmitter can prevent the intrusion of rainwater, safe and durable 15. Product Dimensions: Transmitter: 9 x 5.6 x 2 cm, Receiver: 6.4 x 3.9 x 1.45 cm