Mini Dirt Bike CNC Air Filter Stack. This particular stack pipe is the best air filter stack available. They are designed to maximise the air flow to exactly the right sparts of the carb & by doing this it maximises the carb's performance. They are only designed to fit the standard mini moto dirt bike carb, which is identifiable by it's white fuel tap on the side. These will not fit the KXD or Cobra carbs. Available in a choice of colours including, red, blue, silver & gold. These alloy stacks look great on any bike & will add a little bling to your machine. The stacks are supplied with attachment screws. Summary Best air filter stack available Maximises air flow Choice of 4 fab colours