Bore (in): 3.970 Bore (mm): 100.838mm File Fit: No Gapless: No,  Top Ring Included: Yes,  Top Ring Thickness: 5/64, Top Ring Material: Iron, Top Ring Facing Material: Moly Second Ring Included: Yes, Second Ring Thickness: 5/64, Second Ring Material: Iron, Second Ring Facing Material: Cast iron, Oil Ring Included: Yes, Oil Ring Thickness: 3/16, Oil Ring Tension: Standard, Oil Ring Material: Stainless steel, Quantity: Sold as a set. Sealed Power Performance piston rings are made from ductile iron, and compression rings are available with moly, chrome, and plasma-moly facings for extra durability. These OE-quality sets will seal mild- to high-compression engines and help protect against oil blowby. They feature standard ring end gaps for easy installation. Find the bore dimension and ring thicknesses needed for your application.