Wiseco K1684 3.518" Bore 10:1 Compression Ratio Reverse Dome Forged Piston Kit Fits: All Harley-Davidson 883 Evo Sportster engines 1986-2013 73 cubic inch (1200 cubic capacity) big bore kit includes 10:1 compression ratio reverse dome pistons, rings, circlips, chrome piston pins 2008-2013 must use 1200 cubic capacity Sportster cylinders to install these pistons/kits 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