The Spectre Magna-Clamp 3166 is designed to fit 1/2 inch inside diameter as well as AN-10 heater and oil hose that have a maximum outside diameter of 0.841 inches including any covering. The stainless steel gear drive clamp features a two-piece blue anodized aluminum housing that provides secure tightening at an affordable price. Magna-Clamps are designed to perform as well as they look and are ideal for race, street, and show.