This is a portable device used to produce a loud warning sound without needing an external power source.
It operates by manually turning a crank, which engages internal gears to produce a loud sound.
The sound output can be up to 120 dB at 1 meter.
These sirens are often used in situations where there is no power supply, such as for civil defense, mountain rescue, or in remote locations.
The device is portable, often weighing around 11 kg, and can be easily transported.