Roll-formed, solid 26 gauge, rigid-rib grade 80 galvanized steel door has a siliconized polyester paint finish. Features sealed bearings for smooth, quiet operation and heavy-duty axle, springs, brackets, drums and guides. All have standard chain hoist. 2-3/4" deep heavy-duty zinc-coated steel guides with polypropylene guide runners for smooth operation. Weather seal kit provides protection from wind and corrosion, as well as eliminating dust infiltration. 12 gauge, zinc-coated steel slide interior lock. Minimal back room requirements. Easy to install with little to no maintenance. Supported by 30/25-year paint, 3-year material and 10-year EP3 spring warranties.EP3 spring technology halts damaging corrosion at military approved levels.