Made from full SUS304 stainless steel. Stainless steel smooth 2.5" design N/A test pipe Superior 2.5" design will improve engine response and performance 2.5" tube compatible with oem and after market exhaust Extra thick 3/8 flanges hand tig welded to resist warpage and cracking All necessary gaskets and hardware are included as seen in the picture Designed for outstanding torque and hp gain. All hand tig welded for smooth high quality welds. Light Weight Designed and Highly Heat Resistant. Designed for Fast Air Flow Increase 7-15 HP Gaskets and bolts included 12.5" Total Length from flange to flange. Note: not intended for street applications this item is intended for racing and competition purposes only!