Features Wireless easy installation High frequency vibration body penetrating ability up to 70 110 meters remote control in the open air 4 kinds of volume adjustable the sound is loud and clear 36 music ringtones optional while the music is on the LED flashes simultaneously Perfect for big and high floor houses offices factories hotels etc Transmitter powered by 1 23A 12V battery NOT included and the Receiver powered by 2 AAA batteries Not included Specifications Model 513EMaterial ABS Acrylonitrile Butadiene Styrene plastic Color BlackBlueFrequency 315 HzVoltage 3VPower consumption 0 5 W Size Transmitter 7 x 3 5 x 2cm 2 76 x 1 38 x 0 79Receiver 8 5 x 5 x 2cm 3 35 x 1 97 x 0 79 Operation After the batteries are installed turn the receiver switch to the selection position each press for a ringtone if you want to fix a music the switch to the sound position music symbol Can be fixed Note 1 Do not be close to metal objects avoid Metal magnetic field affect the doorbell results 2 Do not place the doorbell in the sun and rain Packaged included 1Door Bell Transmitter 1 23A 12V battery NOT included 1Door Bell Receiver 2 AAA batteries Not included Detail Pictures