Wiseco K1746 3.498" Bore 10.5:1 Compression Ratio Domed Forged Piston Kit Fits: All Harley-Davidson 1200 cubic capacity Sportster engines 2004-2013 73 cubic inch (1200 cubic capacity) kit includes 10.5:1 compression ratio domed pistons, rings, circlips, chrome piston pins Dedicated forgings are used for superior strength to weight ratio utilizing aerospace alloy with a dome designed for improved flame travel and detailed skirt shape and profiles for stability and smooth operation in the cylinder bore Utilizes the new ArmorGlide skirt coating, the ultimate in toughness, lubrication, and bond technology working together to minimize friction, maximize horsepower, providing improved wear resistance