Features: 1. No wiring required, easy installation 2. Long distance, open up to 70-110M 3. High frequency vibration body, strong penetrating ability 4.32 music ringtones optional 5. When the music is playing, the LED lights will flash at the same time. Product Name: Crystal Oscillator Wireless Flashing Light Doorbell Product Specifications: Receiver: 2 x AA batteries Transmitter: 1 x 12V23A battery (included) Frequency: 315 Hz As it is designed with a high frequency vibrator, it brings strong penetration and far reception range. Equipped with 32 melodies, you can adapt as you like. It brings more convenience for people who have weaker hearing, because it is designed with LED flash and music synchronization. What makes it easy to install is the wireless design. Made of high quality ABS, it is durable. The product length is 9.5cm, the width is 5.6cm, and the thickness is 2.5cm. The wireless doorbell is not only suitable for home use, but also for passageways, restaurants, shops, hotels and others larger commercial spaces.