A piston, comprising: a shaft side with a first circumferential groove, said first circumferential groove bounded by a continuous circumferential seal plateau, said seal plateau extending axially outward from said first circumferential groove, wherein a planar outboard surface extends radially outboard from said seal plateau; a clutch side having two grooves alternating with two lands; an inner circumferential surface having a seal groove formed therein; and an outer circumferential surface having a seal groove formed therein, wherein the sides and surfaces form a ring shape.