WISECO replacement ring set (TD) * TD sets consist of two chrome-faced high temperature alloy internally notched compression rings .047" (1.2mm) * Suitable for CAST IRON, NIKASIL, and ELECRTOFUSION liners. Please note: Only WISECO replacement ring sets may be used on WISECO pistons. 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.