Invidia Subaru WRX and STI headers are fabricated of polished SUS304 stainless steel for optimal durability, feature thick flanges, and include all necessary gaskets. A heat insulator is included for additional protection. The Invidia WRX & STI header is a very nice piece, but if it is more than you would like to spend, we suggest checking out our other headers that offer similar quality at a more reasonable price. This is an unequal length manifold for the WRX and STI which includes gaskets. The HKS WRX & STI exhaust manifold will bolt to a stock or stock-location uppipe.