This fitting is used in V2, V3 and M240 versions of the Fusion Engine. It is the internal fitting that threads into the engine's cylinder to which the 6mm air input line attaches.To replace this fitting, first remove the air line by depressing the black collar and pulling the air line from the fitting. Then insert a 4mm allen wrench into the center of the fitting and loosen by turning counter-clockwise. When installing the new fitting, PolarStar specifies that the fitting should only be tightened to 30 ft/lbs. A new crush ring is included with the fitting and should be replaced with the fitting.
