RPM customers started notifying us that they needed stronger a arms that could handle the weight and the punishment these massive trucks can dish out we reviewed numerous photos of damage to stock a arms to see where the weak points were then reviewed a set of new a arms to see what we could do to improve both strength and durability Features . Replaces the upper a arm from stock traxxas. Replaces the lower a arm from stock traxxas Specifications . Color Black. Weight 0