This product was designed to create more space in the engine compartment. Combining two reservoirs into a single component frees up space for intercooler tube placement, easier maintenance, access to the engine, and durability. The OEM plastic reservoirs are replaced with CNC laser cut and formed aluminum that is TIG welded by hand to provide reliability under the most severe conditions. CNC machined cap retainers assure these caps will never pop off. All fittings and hoses are DOT approved, meaning they cost more, but are actually designed to provide reliability under extreme temperatures and chemical exposure.