Rear, I.R.S., 69 & Later. Improve handling and control body sway while preventing wheel hop under hard cornering. The Type 1 and 3 sway bars are made from heavy 3/4" steel, the Type 2 is made from beefy 7/8". All EMPI High Performance Sway Bars feature zinc plated steel components and hardware along with red urethane bushings.