Ensuring you are Ready for the Road Ahead , the Transglobal 187” x 31” x 96” Dual Spring Operator Assembly is the crucial component to safely roll up your semi truck’s trailer door with ease. This roll door replacement operator assembly contains (2) cable drum and bearing assemblies, (2) 2-3/16” ID springs, and (2) winding cones. The patented “winder” of the dual spring balance operator offers easier, faster installation for your heavy duty trucking needs. FleetPride is your First Click in Heavy Duty .