A new line of truck and trailer underbody boxes from Highway Products, Inc., offered in over 100 sizes, boasts unique features such as non-sag doors, sturdy mounting systems and a thicker grade of aluminum stock than is commonly used in semi boxes.

The walls and doors of the single and double-door models are made of l/8" thick marine-grade aluminum. Doors close into the frame of the box which provides support that prevents damage to the hinges from the constant jolting and vibration of the road. This prevents the doors from sagging.

With strenghtening cross breaks, the doors are mounted on stainless steel piano-type continuous hinges with 1/4" pins and feature aluminum rain gutters and automotive weather stripping. They also incorporate stainless steel T-handle locks and locking mechanisms.

The boxes derive added strength from an unseen 1/8" thick "C" channel stiffener that runs along the bottom front, along with an internal system of welded gussets. Installation instructions are included.