High Quality: Our wireless doorbell is made of ABS material, which is non-toxic, harmless and recyclable, the material can keep itself against from dust, rain and high temperature. Radio Operating Range: The doorbell receiver is highly sensitive, 1 transmitter button triggers 1 chime units and the radio waves is covered all over the house. 38 Different Tunes & 5 Volume Levels: Our wireless doorbell is provided with 38 different ringtones with 3 levels adjustable volume from 20db- 80db. You can enjoy the tone music and set your favorite tones as you wish. Energy Saving & Long Life: Ultra-low power consumption design, Sustainable Use of Energy. The transmitter battery can be used for over 15 months. Our wireless doorbell material is very durable, it can bear over 100 thousand times click. Installation & 100% Guarantee: No batteries required for the 1 doorbell receiver, and easy to plug receivers into an electrical outlet.