Product Description: 1. Unique modern design, exquisite color box packing 2. High doorbell with plug quality, approved by CE, FCC, RoHS,ISO9001 3. 16 chord high-quality melodies (52 pcs) 4. 280~300m radio distance,with LED flash light 5. 4-level volume control 6. Plug and play. Transmitter can be pasted onto the wall or door and receivers is plug-in. 7. Durable battery and Bionic comfortable button 8. Digital circuit, anti-interference system, 9. Avanced code-matching technology, error rate less than 1/120000 10.Super power-saving mode, the power consumption of receiver is less than 3W 11. Transmitters and receivers can be freely matched 12.Brand quality and service, two year warranty period 13. Professional design and mold making department to offer you customized (OEM ODM) service.