Manual Hand Crank Operated air raid siren. Will produces a loud adjustable sound of 135 decibels. It does not need any outside power source. Has an effective range of almost a mile. Made out of heavy steel housing with aluminum stand. Ideal for getting peoples attention, or alerting workers for lunch time, or sheering your team in a sport event, and also good for many other uses. It clamps-on, and mounts to a provided metal rail stand. Two minute installation and you are set to sound the siren.