Designed to help the flow of your cooling system. The divider protrudes into the intake to separate water flow side to side. So there is less interference and back pressure. Works well with WM9 radiator restrictors. Will fit cast iron or aluminum intakes.Pit Stop USA offers Wehrs Machine Intake Divider WM74 at low everyday prices. Be sure to check out all of our products from Wehrs Machine including Wehrs Machine Water Flow Restrictors.