AUTOMATIC POWER - This is a wireless doorbell, but it does not require any battery or battery drain! By pressing the push button, it converts kinetic energy into an electrical signal to ring your wireless doorbell. So you no longer have to worry about the push button running out of power and the hassle of buying strange batteries for the push button. You will always hear your bells! IP64 WATERPROOF AND LED TIME DISPLAY - The IP64 waterproof protection class makes the transmitter rainproof and weatherproof, which is made of ABS + PC plastic, is permanent and works at temperatures between -20 ° C and + 65 ° C. The LED time display screen, which shows the time when the receiver does not ring, can be used as a clock 38 MELODIES AND 4 VOLUME LEVELS - Choose your favorite sound from 38 different chimes and a volume you like from four levels (0-110 dB). The memory function of our wireless external doorbell records the last melody and volume level as well as the time after a power failure 150