Heavy-duty upper Maxx^® suspension arms utilize our latest proprietary composite material for extreme durability. Traxxas designed this composite specifically for high loads and hard landings with just the right amount of flex to resist breaking—even in cold weather. Whether you’re sending it at the skate park, or launching off a ramp, these arms are built for extreme punishment. Fits upper left or right, front or rear. Does not fit Maxx models with WideMaxx.