All New! Fleece Performance stainless steel turbo stud kit for S-300 and S-400 turbos. Our studs are produced in the USA from aged 630 stainless steel and feature a 4mm internal hex head for easy installation. Impervious to rust and corrosion, these studs not only look good, but allow for higher clamping force. Maximum turbo flange thickness of 3/8" Hot re-torque required.