DO NOT ORDER HERE when ordering your manifold you will have the option to order a dump on the manifold page. Neukin dumps are 1.5" diameter 304 stainless steel and feature a SS flange. Most wastegate and setups will offer a dumptube. The tube connects to the wastegate and vents the unused exhaust gas down. The air from the car moving will then blow the exhaust under the car. These are external dumps. To be used on off road cars only.