Easy to InstallSimply plug the receiver into the outlet, then use the supplied tape or screws to secure the transmitter to the wall or door frame. No worries about cables 400m Wireless RangeThe penetrating wireless signal can transmit up to 400m in open space or even long distance, you won't miss any visitor even if you are in a few rooms or on another distant floor. The chime will not interfere with other devices in your house or your neighbors 55 melodies and 5 volume levelsdoorbell receiver, the sound is full and clear; press the follow or back button to choose between melodies; 5 volume settings, the maximum volume is 110dB; whenever someone is there, enjoy the pleasant ringtone. doorbell Waterproof & LED DesignThe wireless transmitter is made of high quality materials, waterproof up to IP55 standard, to ensure stable performance for outdoor use. Blue LEDs on buttons and receivers are visual cues for hosts and visitors, and a fun, thoughtful design for the hearing impaired. HIGH-PERFORMANCE TRANSMITTERReplaceable alkaline batteries last for life of up to 3 years, thanks to the ringer's extremely low power consumption. The doorbell will remember your last melody and volume after a power outage