WISECO REPLACEMENT RING SET. ØØXPØtypeØsets consist ofØTop Ring, Compression Ring, and Oil Ring. Ø Top Ring:ØCast iron, plasma moly faced. Ø Compression Ring:ØCast iron, reverse torsion. Ø Oil Ring: 3-pieceØoil assembly; Stainless steel flex-vent spacer,Øchrome faced rails. Ø The ring type and bore size (in mm) is stamped on the dome of the piston. Ø Refer to this information to order the correct replacement rings. Ø Ring styles cannot be interchanged. ØPlease note: Only WISECO replacement ring sets may be used on WISECO pistons.