•55 ringtones available: Users can set any music as the doorbell ringtone according to their personal preferences •Adjustable volume: 5 levels of adjustable volume,the loudest volume is 110db •Large metal speaker: Good resonance effect,clear and loud sound quality •Strong sound penetrating force: Using high-frequency transmission technology,there is no need to worry about the doorbell not ringing •Long working distance: The working distance can reach 300 meters in an open and barrier-free environment,the signal is stable and does not interfere with each other •Rainproof: The transmitter is rainproof,rainy days can also be used normally •Flashing light design: The light flashing reminder can be used for mute mode Specifications: •Material: ABS •Transmitter waterproof level: IP55 •Working distance: 300 meters (open and barrier-free) •Volume: 0-110dB,five-level adjustment •Receiver voltage: 110-240V/60Hz •Transmitter battery: 1 x 12V 23A alkaline zinc-manganese battery (included) •Ringtones: 55 polyphonic music •Working frequency: 433.92MHz±280KHZ •Working temperature: -20 to +70℃ •Transmitter size: 70x40x15mm •Receiver size: 70x70x30mm Package included: •2 x Transmitter (with Battery) •1 x Receiver •1 x Pack of Installation Accessories •1 x English User Manual