Hand operated siren LK-100 is no electrically powered warning device to provide effective sound signal warning to fit virtually any signaling application and alert need Specification Sound Rating: 110±2dB(A) @1M Output Frequency: 550±20Hz (Dependent on Rotation Speed) Sound range:500M Net Weight: 1.2Kg Carton Size: 18.6x18.6x17CM Features : no power supply required light weight for portability powerful low frequency sound Shutter mechanism to provide a choice of signals:continuous and warble Application: Camp site,civil defence,mountain rescue,coast guard warning,quarries/mining