Forge Motorsport Volkswagen Golf R/GTI Secondary Air Flow Kit (Mk7/7.5)Forge Motorsport secondary air filter for the Golf Mk7 with Secondary Air Injection (SAI). Some VW Golf Mk7s have a secondary air intake pipe connected to the side of the stock airbox. If you have an aftermarket intake kit that does not cater for this, then simply fit this kit to the end of the pipe to allow the air to be filtered. This foam filter and adapter is required for most aftermarket intakes including the Forge Motorsport Intake kit.