Trick Shift was originally developed by B&M for racing, but it has also proven useful for towing, light trucks, RVs, and other applications. This automatic transmission fluid is a scientific blend of foam inhibitors, pressure agents, and shift modifiers that provide a firmer shift for improved shift feel and extended transmission life. It can be added to stock-type transmission fluids, but it is not an additive, so for best results and maximum improvement it is best to use Trick Shift exclusively.