Update your semi's spring-operated door assembly with increased reliability and smoothness, with the Transglobal 4.5" Steel Roll Up Door Bottom Fixture that ensures you're Ready for the Road Ahead. This replacement bottom fixtures ensures your roll up door can easily open and close, without damaging itself on the way down. Manufactured with corrosion and rust-resistant metals for extended use in harsh conditions and humid climates. FleetPride is your First Click in Heavy Duty.