Mallard It is just as it says .You lock the converter up in high gear there is NO slippage.You get better gas milage,less heat build up(slipping converter build heat)Its also can be done without a computer with a kit from TPI .We use them all the time in rods.The thing with a lockup is it has to disengage as you slow down or when you come to a stop the tranny will kill the motor till you unlock the converter.They use a pressure switch on the side of the tranny wired to a valve inside that disengages the converter when the pressure starts to build(like when you step on the brakes) smile