Featuring polypropylene J-Hooks, HingeMaster™ latches onto sides of barn door-style trailer, closing off hinge gaps and maintaining snug seal while allowing full unrestricted access to rear of trailer. Foam side frames withstand impact, while raked head frame diverts rainwater away from loading dock floor. With consistent top-to-bottom seal, system is compatible with facilities requiring strict climate control and/or high cleanliness levels, such as food, beverage, and pharmaceuticals storage.