Mahle Original Standard Piston Ring Sets 0.20 # 50564.020Piston Rings, Standard Piston Ring Sets, Cast Iron, 4. 020 in. Bore, 5 64 in., 5 64 in., 3 16 in. Thickness, V8, Set 50564. 020 Bore (in.): 4. 020 in. Bore (mm): 102. 108mm 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: Cast iron Second Ring Included: Yes Second Ring Thickness: 5 64 in. Second Ring Material: Cast iron Second Ring Facing Material: Iron