Prepare your semi to be Ready for the Road Ahead , with the Whiting 3.3" Steel Roll Up Door Center Hinge that provides your vehicle with a smooth and reliable spring-operated door assembly. This replacement hinge ensures your roll up door can effortlessly move up and down, without jamming or locking in place. Engineered with corrosion and rust-resistant metals for enhanced durability in humid climates and rough conditions. FleetPride is your First Click in Heavy Duty .