30" x 30" Galvanized Roof Hatch - Acudor Rough Opening Size=N/A";" Material: Cover's outer skin is 14 gauge Galvanized steel. Inner skin is 22 gauge galvanized steel., Finish: Prime coated Galvanized Steel Lock / latch: Self Latching zinc plated outside T handle with stainless steel inside lock and lever assembly. Unit also has inside and outside padlock provisions. Hinge: Zinc Plated Steel Flange: