Mahle Original Premium Piston Ring Set # 40564.060Piston Rings, Plasma moly, 4. 060 in. Bore, 5 64 in., 5 64 in., 3 16 in. Thickness, 8 Cylinder, Set Bore (in.): 4. 060 in. Bore (mm): 103. 124mm File Fit: No Gapless: No Gas Ported: No Top Ring Included: Yes Top Ring Thickness: 5 64 in. Top Ring Material: Cast iron Top Ring Facing Material: Plasma moly Second Ring Included: Yes Second Ring Thickness: 5 64 in. Second Ring Material: Cast iron Second Ring Facing Material: Iron Oil Ring Included: Yes Oil