Hand Operated Siren-120A also known as a hand-cranked siren or air raid siren.
This is a portable and power freed-device used for emergency warnings, civil defense, disaster management, or crowd control.
The sound is produced by manual cranking a handle, which rotate a fan or impeller to create a loud destintive warning sound.
It is an effective attention-getter, with the volume often adjustable by a rotation speed of the handle.