Cylinder Works Standard Bore Cylinder Kit. This cylinder looks virtually identical to the O.E.M. and is nickel silicon carbide coated for long life. Super convenient - just purchase and install. Virtually identical in appearance to stock. Nickel silicon carbide-plated for long life. Honed to exact size for easy piston installation. All kits come complete with gaskets, cylinder, Vertex piston, rings, pin and clips. Detailed Specifications: Compression ratio (x:y): 10.7:1. Cylinder diameter (mm): 85. Displacement (cc): 800. Piston diameter (mm): N/A. Includes: Front Cylinder, Rear Cylinder, two (2x) Piston Kits and Top End Gasket Kit. Note: Uses Vertex #24487.