Get Ready for the Road Ahead™ with a smooth and reliable spring-operated door assembly, with the Whiting 4" Steel Roll Up Door Complete Bottom Bracket Assembly. To ensure your roll up door keeps your cargo safe, this replacement bracket assembly mounts to the bottom of the door for added security. Fashioned with rust and corrosion-resistant metals for extended use in rugged climates and harsh conditions. FleetPride is your First Click in Heavy Duty®.