Self-Generated Electricity - It’s a wireless doorbell, but no more battery needed or battery drain! Batteries and no more hassle about buying weird batteries to run your button you will hear always your bells! IP64 Waterproof Display Screen IP64 - IP64 Waterproof Screen IP64 Rating IP64 makes the transmitter resistant to rain and atrocious weather conditions, made of ABS+PC plastic, durable to use, works in temperatures between -20 °C to + 65 ° C. The time display LED Screen, the time appears when the receiver does not ring, can be used as a clock 38 Melodies and 4 volume levels - Select your favorite sound from 38 different chimes and the volume you like from four levels (0-110dB). And the memory function of our outdoor wireless doorbell can memorize the last melody and volume level and time after a power failure 150 Meters Wireless Range - The penetrating wireless chime signal can be transmitted up to 492ft/150m in open space and long distance even with many obstacles (doors, walls,