Control arm is made by high density steel. Collocation with hardened rubber bushing (street racing) or anti-dust pillow ball bushing (drifting). Provide advanced stability during high speed driving or hard cornering. Immediately response from driver's steering control under acceleration. Adjustable links are assembled with wave washes between nuts and bolts, which enable both of them can tight more harder, won't come loosen or back off. In additional, WAVE WASHERS allow many times loosen and tighten again, unlike competitor's products are difficult to loosen or tighten while doing the next alignment in the future.