The contrasting black and stainless look of this rotor is stunning. Perfect for Hot Rod Bikes The Black mamba rotors are specially created by using a mambasite coating to create a black rotor from stainless steel. The black rotor is then machines with cooling slots that allow the hot gases to escape rather than become trapped in the ordinary cooling holes. The mambacite coting is similar to a wear in and that makes it quite durable so your rotor actually looks better as you use it.