Wireless Doorbell NO Battery Waterproof EU Plug Led Light 300m Long Range Smart 433mhz|Doorbell LED wireless doorbell light for your homeBy EMASTIFF Features and specifications: 38 ringtones to choose from and 3-step volume control (0~85dB) Eye-catching backlight flashes when someone pushes the doorbell. Particularly suitable for the elderly, deaf, and pregnant women If paired with multiple push units in one system, the chime can be set individually for each push unit Uses machine-learning to prevent interference from other wireless transmitters Automatically saves selected ringtone after powering off Designed to last up to 25 years Working frequency: 433 MHz Receiving distance: 300M(in open area) Transmitter size: 75 x 51 x 20 mm Receiver size: 95 x 65 x 24 mm Receivers Rated voltage :AC 110V-220V -240V The transmitter 12V23A battery factory pre-installed(battery not included)