One of the benefits of the Tippmann FT-12 is that it doesn't have a gas line hose. The gas line can eventually break and leak on you so it's best to be sure you have one just in case in your gear...
The Tippmann FT-12 uses a unique barrel nut that allows the marker flip open! Over a period of time the plastic can get worn out or cracked if over tighten. Replace the part or your gun might flip...