Feature: The working distance in open areas can reach 300m. With a strong and stable wireless signal, you can hear the ringtone clearly even if you are several rooms away or on another floor; 60 tones: 0 - 110 dB; WATERPROOF BUTTON: The transmitter is waterproof to ensure perfect outdoor performance. But please avoid watering the product directly. The doorbell can work from -20 ℃ to +60 ℃ to withstand all weather conditions; Easy to install and set up: Simply plug the receiver into a power outlet and use the provided screws or adhesive strips to attach the transmitter to an outdoor wall; no need to reset the tone and volume after a power outage; Compact and easy to use, the socket receiver will not block other sockets. Notes: The transmitter cannot be installed on metal doors; Keep the receiver away from electrical equipment with strong electromagnetic radiation (TV, computer, audio, etc.); The effective receiving distance of the signal will be affected by environmental factors.