The Waterproof Door Calling Bell Wireless 433mhz Intelligent Door Bell is a smart home wireless doorbell that offers a range of 300 meters. With its adjustable tone, you can easily change the music and prevent any string noise. The installation is simple and hassle-free. This doorbell comes with various features including an indicator, receiver, volume key, selection key, and launcher button. It has a strong penetration performance, allowing it to receive signals up to 300 meters. Please note that the actual received signal may vary depending on the visual environment and obstacles. The Waterproof Door Calling Bell is easy to install. Simply press the button and the bell will ring in the room where the receiver is installed. The receiver intelligently flashes and the bell lights up, providing a convenient and visible notification. This doorbell is suitable for a variety of applications including family homes, office buildings, restaurants, and factories. The specifications of the Waterproof Door Calling Bell are as follows: Model A20, working range of 300 meters, 36 ringtones to choose from, 4 tone volume adjustable sizes. The transmitter requires a 12V23A battery, while the receiver operates on 110/220v. The size of the transmitter is 7.7*4.6*2cm and the receiver is 9*5.6*2cm. The package includes 1 receiver, 1 emitter, and 1 double-sided adhesive for easy installation. Key Features: 300 meters range Adjustable tone Indicator, receiver, volume key, selection key, launcher button Easy installation Strong penetration performance 36 ringtones to choose from 4 tone volume adjustable sizes Suitable for various applications