300M Signal Wireless Doorbell Waterproof 4-Speed Volume 60 Chord Memory Function Features: 1. Easy to install and use, only two steps, one sticky and one plug, ready to use. 2.433MHz RF signal, 300M signal through the wall (the use distance depends on the actual use environment). 3. Four adjustable volume levels, 60 chords, the whole house can hear. 4. Silent mode, only flashing lights do not ring the bell, to avoid waking the sleeping baby or family. 5. Daily sun protection, rain and water, do not fear the sun and rain. Specification: Volume: 0-110 decibels, four adjustable Model distance: 300 meters in the open without interference Temperature: -20℃~50℃ Ringing tone: 60 chords of music Receiver: 110-240V, 50/60HZ Wireless frequency: 433MHZ Color: Gold / Silver / Black Package included: 1*doorbell transmitter 1*doorbell receiver Note: 1. Please allow 1-3mm error due to manual measurement. Please make sure you don't mind before ordering. 2. Please allow 1-3g weight error. Please make sure you don't mind before ordering. 3. Due to different lighting of photos and differences in monitors, the pictures may not reflect the actual color of the object. Please make sure you don't mind before ordering, thanks!