This cap does not fit Maximus models. The WIDE-BORE GAUGE PORT we have listed will fit to increase air-flow to the valve for more power.
For Discovery models this eliminates the pressure gauge and increases air-flow to the valve producing more power. Our WIDE-BORE GAUGE PORT produces the same performance and allows you to have a pressure gauge. Some need or prefer to eliminate the gauge for simplicity or to allow the use of a wider variety of stock and forearm options. This cap is made of 6061-T6 aluminum for excellent strength and corrosion resistance.
With this cap installed the gun will not have a pressure gauge. It should be filled with a hand pump or tank that has a gauge to monitor fill pressure, most do.