The U.S. Military uses these Pressure Relief Valves to equalize interior air pressure of shelters. They are designed to release under excessive pressure or temperature by opening at a predetermined pressure/temperature. Once the pressure is relieved or temperature is reduced, the thermostatically operated valve closes. These valves fit a wall thickness of 0.006" - 1.5". If your walls are thicker than 1.5", you'll need to supply longer bolts.