Unless you have 4 hands, installing the manifolds can sometimes be challenging! You thread the plate over the manifold stud and the thumb screws tighten against the exhaust and intake manifold individually. This allows you to align the manifolds to where they need to be and then you can install the clamps and nuts on the other two remaining studs. Once you have two clamps installed, these units get removed and replaced with the original clamps and nuts. These are not meant to be left on. USA