Enduro is designed for extreme durability. Used in pro street, heavy nitrous and blown applications. 100% American made forging, is the same as one used to make the Crower Ultra-Light crank shafts. The only difference is the amount of machining time and less debur. 1/8" radii, heat-treat, "counterweight correct" design and straight shot oiling. Comes standard with four lightening holes. Weight: 57-59lbs (determined by stroke, rod, and main size)