Pro-Flex’s yellow jacket version (Pro-Flex 1) and a new black jacket arc-resistant version (Flak Jacket) can be used with either natural gas or liquid propane (LP) and utilize the same dual-seal, gasket and O-ring connection system that virtually eliminates the problem of leaks due to bad cuts. The tubing is annealed, which allows it to bend and stay bent. It comes in a variety of lengths, including 25’. All male fittings are inside-tapped, which allows them to serve dual uses. For example, a ½” male fitting can also be used as a 3/8” female fitting, a ¾” male as a ½” female fitting, etc.