Machined from 6061-T6 Aluminum. Each arm adds ½” of length over stock arms giving the Slash 4x4 a 1” wider stance. This increases the stability of the truck and can add up to ¾” of wheel travel depending on your shock set up. You will need longer camber and steering links for this set up. We recommend the Traxxas turnbuckles. These are Traxxas part number 2336A (RC Solutions #198). You can find a PDF file under Product Support that gives the correct setup length for these. You will also need to modify your body for these arms to work properly. The amount of modification depends on your suspension setup. See pictures below of unmodified vs. modified bodies.