FTF billet aluminium fuel cap design was inspired by Aero type caps used by WWii fighter aircrafts. The cap sits in a mounting flange, sealed with an O-ring. An integrated ventilation system allows air inlet into the tank but also in case of a vehicle rollover the loss of fuel is limited by the valve controlling the ventilation. The mounting ring has a 55mm diameter opening and an overall diameter of 140mm. Cap assemblies are supplied with a cork gasket, full set of stainless Hex head screws, nyloc nuts and PTFE sealing washers. To release the filler cap, lift the mechanism and turn counterclockwise. To secure the filler cap return the mechanism clockwise and snap the mechanism shut.