1. **Versatile Doorbell Solution**: Our doorbell serves as a reliable intercom phone, for use in offices or warehouses. It can be conveniently set up at your main door for enhanced security purposes. 2. **Extended Range**: This doorbell can be extended up to 3000 meters using wired connections, ensuring that you stay connected no matter where you are within your premises. <+-3dB (300-3400) and noise voltage under 10MV, our doorbell guarantees clear sound quality for effective communication. 4. **Easy Installation**: Powered by either 220AC or four R6P size AA1 5V alkaline batteries, this doorbell is designed for straightforward installation and operation, making it user-friendly for everyone. 5. **Efficient Talk Back Functionality**: Enjoy seamless conversations with the talk back feature of our doorbell. Simply press the push button to alert the other party, ensuring efficient communication when needed., Manufacturer: CUIchwWE