These split flow high volume nozzles divide the fuel flow around the valve stem and valve guide. When used in our 57mm throttle body the fuel is directed into the highest flow areas of the port and directly at both sides of the valve opening giving you the ultimate in fuel distribution. Drivability and horsepower are enhanced. They flow enough fuel for even the nastiest of street motors. Will also fit stock 2006 and later Harley® and SE 50mm throttle bodies.