Cover & Liner: 11-gauge (0.090") aluminum cover with an 18-gauge (0.040") aluminum liner
Curb: 11-gauge (0.090") aluminum, Optional: 11-gauge double wall curb (curb liner at exterior)
Hinge: Tamper-proof hinge contained within hatch as part of a spring assembly
Latch: Turn handle
Spring: Greased compression springs enclosed in telescopic tubes, which counterbalance the door to require no more than 10 pounds of opening force
Hardware: Zinc coated steel, Optional: Stainless steel
Insulation: 1" thick rigid fiberglass in cover and 1" at curb perimeterMounting Flange: 3½" on a single wall curb, 2½" on double wall curb.