We prefer hose to copper supply line tubing because it won't corrode or develop stress/fatigue cracks and it is much easier to install. This UL listed hose is fully assembled and leak tested with solid brass fittings (3/8" female swivel flare each end), and high pressure, thermoplastic, LPG hose. Assemblies are UL Listed. Standard Lengths: 5', 10', 15', 20', 25', 30', 35', 40'. Other lengths and rubber construction are available on quantity special order.