Corrugated flexible Stainless Steel gas heater connector Polymer coated Uniform baked-on polymer coating leaves no gaps to resist corrosion and chemicals and protect against leaks Manufactured without soldered or brazed joints from type 304 Stainless Steel Broader face nuts and fittings with smoother connector ends seal with less torque for easy installation CSA IAS design certified for gas appliances indoor and outdoor 3/8-in inside diameter and 1/2-in outside diameter with fittings 1/2-in FIP x 1/2-in MIP 48-in