Ensure your semi is Ready for the Road Ahead with a smooth and reliable spring-operated door assembly, with the Whiting 3.8" Steel Roll Up Door Lock Keeper Assembly. Thanks to its secure design, this replacement keeper assembly is the ideal choice to prevent your door from opening when driving or moving. Engineered with corrosion and rust-resistant metals for enhanced durability in humid climates and rough conditions. FleetPride is your First Click in Heavy Duty .