The 1200AA430 Crankshaft is used in the 2011 and newer STI engine and can be used as a upgrade for most EJ 2.5 engines this is the latest updated EJ crankshaft from Subaru.This crankshaft is nitride treated to be extremely hard and reduce the chances of wear and damage from foreign material, Through nitriding surface hardness is doubled on the Rockwell scale and fatigue life is increased by 25 percent