P2M - NISSAN SR20DET ROCKER ARM STOPPER (P2-RASNSR20-GD)P2M stainless rocker arm stopper is a direct drop in for all RWD SR20DET. The RAS act as a fail safe measure under high rpm where the rocker arms have tendency to jump out of its place. With the RAS in place cuts down the chance for the rocker to jump out, in the event when it does the RAS cuts down engine damage to the minimal by holding the rocker arms in places nearby and not flying around inside the cylinder head that might lead its way down into