RHADD Specifications:Cover: Double-skin construction (in box type design) with 1" fibreglass insulation and a continuous EPDM foam weatherdraft seal gasket that is attached to the inside of cover to provide a flush, tight fit. Designed to support a live load of 40lbs.sq. ft., the cover is 18" thick aluminum. To accommodate the polycarbonate domes, an aluminum extrusion with built in condensation drainage channel is provided.Curb: 18" Aluminum with 1" thick fiberboard roof insulation at curb exterior. Curb is 12" high, with 3.375" wide bottom flange and pre-drilled mounting holesHinge: Heavy Duty Aluminum pintle hinges with 38" pinOpening: Gas spring operators allow cover to open and close with ease. Inside pull handle allows for easy control when closing cover.Door Latch: Self latching, zinc plated outside T handle with stainless steel inside lock and lever assembly. Unit also has inside and outside padlock provisions.Finish: Mill finish RHGDD Specifications:Cover: Double-skin construction (in box type design) with 1" cellulose insulation and a continuous EPDM foam weatherdraft seal gasket that is attached to the inside of cover to provide a flush, tight fit. Designed to support a live load of 40lbs.sq. ft., the cover is 18 thick aluminum. To accommodate the polycarbonate domes, an aluminum extrusion with built in condensation drainage channel is provided.Curb: 14 gauge galvanized steel with 1" thick fiberboard roof insulation at curb exterior. Curb is 12" high, with 3.375" wide bottom flange and pre-drilled mounting holes.Hinge: Heavy duty galvanized steel pintle hinges with 38" pin