Feature X-style forgings and fully boxed-style (race pistons) forgings for ultimate strength, minimizing friction, durability, power, and weight reduction Pro Race Piston increases the durability by reducing the stresses in the pin bore area Full radius dome designs maximize quench while eliminating hot spots that promote detonation Internal bracing maximizes durability while decreasing friction in the pin assembly Fully-boxed style (race pistons) forgings come standard with skirt coating which reduces friction, which in turn reduces heat Race piston kit includes a DLC pin; this technology has been proven and used because of its high resistance to abrasive wear, which extends the service life and reliability under extreme conditions With the pistons each kit includes wrist pins, rings, circlips & top-end gasket as required Made in the U.S.A.