OASE Flow Regulator, 1 1/2-Inch The Flow Regulator is a simple, but sturdy flow regulator for controlling water flow to filters and water features. The Flow Regulator is also ideal as a tubing connector for connecting non-kink spiral tubing (adapters included). It features both an inlet and an outlet, each with a stepped hose adapter for 1, 1-1/4, and 1-1/2 inch openings.