GKTech - V4.2 - S14 240SX/S15 SILVIA/R33 SKYLINE TENSION RODStThe new V4. 2 GKTECH Tension Rods offer the most amount of clearance available in a tension rod while now being 0. 62" (16mm) thick! Tension rods (aka caster arms) allow adjustment in vehicle castor to bring the wheels forward and increase steering response. In general, the more caster the better. Allowing sharper turn in and faster return to the straight position when letting go of the wheel. V4. 2 arms feature high quality 5 8" Teflon lined pillow