Greddy SR20DET Rocker Arms Stoppers (RAS) are designed to prevent valves from floating which can lead to bent valves and severe engine damage during high-revs. RAS keep the rocker arms in place and lessen the chance of them flying out and cause havoc. A common problem at high-revs on SR20DET that can be easily preventable by installing Rocker Arms Stoppers.
GReddy Rocker Arms Stoppers are specific to S13 SR20DET. Can be made to fit S14 SR20DET with some modification.