EMPI#21-2162. EMPI'S ROCKER ARMS ARE MADE FROM FORGED CHROMOLY & THEN PRECISION GROUND & HEAT TREATED. ROCKER ARMS W/ BUSHINGS. PRECISION GROUND BRONZE BUSHINGS WITH THROUGH HOLE LUBRICATION ENSURES THAT PREMATURE FAILURE OF THE OLD NEEDLE BEARING ROCKER ARM DESIGN IS A THING OF THE PAST!