Professional two-tone sound signal with built-in compressor, very loud - up to 139 dB. The kit includes a relay and mounting elements. TECHNICAL PARAMETERS: sound type: two-tone, harmonized output sound volume: 139 dB output sound range: 530 - 680 Hz ±5% power supply: 12V service life: 100,000 on/off cycles red color DIMENSIONS: length: 15.4 cm width: 9.5 cm (measured "at the outlet") height: 11.2 cm