This is our billet stock size lightweight pulley designed to reduce the rotating weight on the front of the crankshaft. The stock crank pulley weighs in at 4.5lbs. Our billet stock size pulley weighs in at 2lbs resulting in more than half the weight reduction of the stock pulley. This weight reduction allows for more power to be transfered to the tire. With the size of the pulley being the same as stock, there is no issue with the performance of the rest of the accessories being driven. This pulley is a nice additon to the modder looking for additonal power increases while maintaining a budget.