The TCU offers the ability to manually shift the trans via an electrical switch. The paddle shifters are ideal and simply plug into the harness. It also has the ability to store two separate programs that can be selected by an externally-mounted switch. For example, one soft shifting program for commuting, and one to unleash a neck-snapping strip tune. You also have the option of turning off your overdrive all together, or locking and unlocking your converter.