Features: Up to 10-Year battery life. Low power consumption of receiver. 48 chimes for your choice 5 volume levels from 0-97dB (included silent mode). Receiver designed with night light function. 7 adjustable brightness for night light function (included OFF mode). Up to 600ft Wireless Range in Open Space DIY pairing, add up to 32 additional wireless infrared sensors /doorbell buttons/ magnetic sensors/ to your own alert system Smart memory function, no need to configure doorbell settings (Chimes, Volume, Lightness) again if unplugged. Music rhythm flashlight on receiver (bright light flash when the doorbell is pressed, no matter it is with volume up or in silent mode/ night light mode) Package Contains :2 x Magnetic Transmitter 、1 x Receiver 、4 x Double-sided Adhesive Tape、1 x User Manu.