These are the Black Traxxas Heavy Duty Front Suspension Arms for many Traxxas kits. Heavy-duty Drag Slash suspension arms incorporate our latest proprietary composite material. Traxxas designed this composite with just the right amount of flex to resist breaking, even in cold weather. Brightly colored and extra-tough, HD suspension arms add substance and style to your Bandit or Drag Slash. Requires #3632 series caster block and #3640 screw pin set.