WISECO REPLACEMENT RING SET. ØØXCØtypeØsets consist ofØTop Ring, Compression Ring, and Oil Ring. Ø Top Ring: Chrome-faced high temperature steel alloy. Ø Compression Ring: Taper-faced ferrox coated cast iron. Ø Oil Ring: 3-piece low tension oil ring. 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.