#K0117 AOD / AODE / 4R70W Superior Billet Aluminum 2-3 accumulator piston. The new “Shorty Style” late type Billet Aluminum 2-3 accumulator piston w/4 ring / seal design. Stop using and worrying about delaminating of “O.E.” type boned pistons, as well as seals a slightly worn bore / case allowing you to “save a case” and not go thru expensive reamer and fluff! Perfect for all rebuilds. Fits all FORD 4R70 and 4R75 units and retro back to AODE / AOD.