All Precision Roof Hatches are fabricated of heavy gauge steel or aluminum properly finished to withstand rough handling and exposure to the elements. Insulation in the cover and curb minimizes the effects on the building's HVAC system. A rubber gasket, in its own formed track, tightly seals the lid against the curb, making the unit weather tight. The cover is devoid of all hardware except for the handle, negating areas where corrosion and rust can form. All hatches are provided with padlock provisions both internally and externally. Hatches of length 4' 6" or less are equipped with a 1 point zinc-plated cablock and any hatch longer than this are equipped with a 2 point cablock. Each roof hatch is tested in the plant to assure smooth opening and closing with one hand. When the length of a hatch reaches 5' 5" or longer, a 2 point slam-lock is used.