The ATI 42 Gallon Auxiliary Diesel Fuel Tank & Toolbox Combo delivers extended diesel driving range while providing integrated, secure tool storage in a single, space-efficient unit. Designed for work trucks that require both fuel capacity and organized bed storage, this combo system connects to the factory fuel tank using a Gravity Feed Installation Kit (sold separately), allowing diesel fuel to transfer naturally into the primary tank without pumps or electrical components. Constructed from premium aluminum, the auxiliary fuel tank is DOT approved for highway and commercial use , meeting and exceeding Title 49 CFR 393.65 requirements. The built-in toolbox offers durable, weather-resistant storage for tools and equipment. Engineered exclusively for auxiliary diesel fuel applications , ATI delivers dependable, American-made performance built for demanding work environments.