Aluminum, designed for effective warning in areas where no power supply is available, maximum sound with minimum effort, lightweight and easily transported to remote locations, miscellaneous applications include: schools, public buildings, camps, mountain rescue, construction workers, etc., sound rating (1M): 100dB +/-2, output frequency: 550 Hz +/-20 Hz, includes carry case, MFR: MIL-TEC by SturmEAN: 4046872191770