Long distance barrier-free 150 meters, Strong penetration, in the open air distance can reach 300 meters. PS: Receiver signals vary depending on the environment, depending on the obstacle. 32 Melodies 4 Volume, The doorbell has 32 ring tones and 4 levels of volume (mute function). Press the transmitter and the receiver will ring and flash light. Waterproof design, The waterproof design of the transmitter can prevent the invasion of rain water and effectively extend the service life of the product. Easy To Install, Just plug the receiver into power socket and attach the transmitter on door, you don't even necessarily have to make holes or damage anything. Featuring multiple chime, handy volume control and long working distance, the wireless doorbell kit is a must-have accessory for home, office, store, etc.