MP3 wireless door bell Description: 1. CE and RoHS compliant. 2. Volume level control. 3. Transmitter IP44 waterproof. 4. iPhone black surface finishing. 5. Built-in 10 selectable polyphony sounds. 6. LED Flash indicator in Both Receiver and Transmitter 7. MP3 format music can be downloaded into the doorbell. 8. Waterproof Transmitter requires CR2032 battery(included), Receiver unit requires 4X1.5V AA batteries(not included), with 2.0USB plug(included). 9. Wireless remote control distance reaches 200M in the open air.