Self-Powered&No batteries required: Self-powered doorbell, batteries are not required for both push button and receiver. Pushing down on the button creates a mechanical force, which generates electrical power itself and sends a stable signal to the receiver. Eliminates the need for changing batteries or recharging 52 Chimes & 5 Level Volume: Wireless doorbell offers a whopping 52 chime sounds, as well as five volume levels. From basic dingdong to more elaborate melodies, listen to several and decide which sound we prefer and also change the volume at will LED Indicator with Mute Mode: Built-in 7 flash LED lights on its receiver， doorbells illuminate with button presses, giving us a visual cue that someone is at the door. An illumination option is particularly important for the baby’s sleeping and nap time IP55 Waterproof&Weather-resistant: Wireless doorbell in IP55 Waterproof can withstand varying weather conditions. Lasting throughout the seasons, door bells wireless cordless won’t be damaged by fluctuating temperatures, rain, or snow. Prolongs the service of time and works perfectly from -20°C to 60°C Easy to Install and Memory Function: Intelligent wireless doorbell with memory function, which preserves our settings in the case of a power outage. Convenient and easy to install, do not require electrical wiring, offering greater liberty for where the homeowner can install the doorbell, Manufacturer: Gobikey