This is the smallest size and lightest weight cooler relative to cooling capacity you can buy! B&M's Supercooler low pressure drop coolers reduce the risk of lube system failure. A controlled amount of automatic transmission fluid (ATF) is allowed to bypass the stacked plate core, passing through a self-regulating orifice, which monitors resistance to flow. Controlled by viscosity, the thicker ATF is returned directly to lube through two open bypass passages positioned in the stacked plate core. As operating temperatures increase, more of the ATF flow is directed through the core. The result is highly efficient cooling technology that combines improved protection against lube system failure with the required levels of optimal heat transfer.