When Tomei designed the Expreme exhaust manifold for the EJ20 motor, they had efficiency in mind. Not only to increase flow but to be light and strong as well. To accomplish this, they have selected SUS304 stainless steel for the construction. With very smooth bends, high quality welds, and extensive testing, Tomei's engineers have created one of the best manifolds available for the EJ turbo motor. This is an un-equal length manifold so the characteristic boxer sound is preserved. Included is all the hardware and gaskets you will need as well as thermal wrap and metal ties to keep heat away from the oil pan and engine bay.