RPM A-arms for the Helion Invictus MT are molded from a blend of engineering grade nylons for unmatched strength and durability. Crucial design elements include oversized bosses around the hinge pins and the pivot balls to help prevent hard hits from ripping them out of the A-arm. RPM also tightened up the tolerances around the hinge pins by more than 0.005” (0.13mm) to reduce slop in the suspension system and improve camber, caster and toe angle consistency. Sold as a set of one upper and one lower A-arm.