Molded from tough, durable high density polyethylene (HDPE), the Tool-Tainer, II and II-L will never dent, rust, need painting or corrode. Withstands temperatures to -40°,. Keyed tongue and groove lid closure keeps your box dry and dust free. They are so big it's like getting two boxes for one. 50%, deeper than standard size boxes. Two sizes fit most compact and full size trucks, both long and short bed. They can be mounted directly behind the cab or at the tailgate. Tool-Tainer, II and II-L will not sag in the middle. Supports are shipped with each box, if required for a specific model. There are no hinges, springs or weather-stripping to wear out or break. This means no failures, no repairs, and no maintenance. 2 Interior tool shelves are included. Locks are keyed alike for convenience. Note: Nevr-Rust will not fit the following: Nissan Frontier, 2014 Ford/Chevy/GMC Extended Cab with short beds.