Part #:46132ST-8 Manley performance piston rings feature a high performance, ductile-iron top ring with a plasma-moly inlay. The second rings are constructed from reverse-twist cast iron, and the oil rings are 3-piece, standard-tension rings. Manley performance rings are available in both standard and file fit sizes. Choose the set designed for your engine application. Bore (in):4.090 in. Bore (mm):103.886mm Piston and Ring Oversize (in):Standard File Fit:Yes Gapless:No Top Ring Included:Yes Top Ring Thickness:1.2mm Top Ring Material:Steel Top Ring Facing Material:Chromium nitride Second Ring Included:No Second Ring Thickness:1.2mm Second Ring Material:Cast iron Second Ring Facing Material:Cast iron Oil Ring Included:Yes Oil Ring Thickness:2.5mm Oil Ring Tension:Standard Oil Ring Tension Rating:12-16 lb.