Our original Skull Exhaust Tip is made out of 356 cast aluminum. This highly detailed skull will give your ride a look that will blow your mind! Our exhaust belching skull will fit without adaptors over a stock 4", 3.5", 3", 2.5", 2.25" or 2" automotive exhaust pipe and will not restrict air flow. This is not a cheap plastic toy. This is the real deal! We guarantee you won't be disappointed.