Tomei - Rocker Arm Stopper - Nissan - SR20DETSpecifications: Manufacturer: Tomei Reference Number: 13220R300 When over revving or miss shifting the SR engine whilst at 7000 RPM and over during circuit runs or drag racing can sometimes cause the tappet side of the rocker arm to jump and rocker arm to come off. This Rocker Arm Stopper is a simple cost effective part which holds the lash adjuster side of Rocker Arm in place with a fixed clearance that prevents the rocker arm from disastrous results