WISECO REPLACEMENT RING SET.* YC type sets consist of Top Ring and Oil Ring.* Top Ring: Alloy steel, phosphate coated, chrome faced, positive twist.* Oil Ring: 3-piece oil assembly; Stainless steel flex-vent spacer, chrome faced rails.* The ring type and bore size (in mm) is stamped on the dome of the piston.* Refer to this information to order the correct replacement rings.* Ring styles cannot be interchanged.* Please note: Only WISECO replacement ring sets may be used on WISECO pistons.