Type DSH is an automatic fire vent from Bilco. It has double leaf smoke vents that are available in steel or aluminum. This fire vent can help firefighters in bringing a fire under control by removing smoke, heat, and gasses. It automatically releases vent covers upon the melting of a UL-listed 165°F (74°C) fusible link. It is fully insulated and gasketed for weather tightness and constructed with corrosion resistant materials.