1.75 in. Primary Tubing. 3 in. Collector Size. Mild Steel. Black Painted Finish. Gaskets. Hardware. Flowtech headers are the perfect combination of performance and value. Flowtech long tube headers are precision engineered using mandrel bent tubing, formed collectors and 5/16" flanges with sealing rings for a leak-free seal. All mounting hardware and gaskets are included for a simple installation. This header is coated in a high heat resistant black paint for a stealthy appearance.