Shimano slx rt70 m7000 centre lock rotorthe sm rt70 ice tech rotors 160 180 and 203mm have a sandwich structure of an aluminium core embedded in 2 stainless steel layers the higher heat dissipation of the aluminium helps to reduce the surface temperature of the rotor by around 100 degrees celsius optional ice tech brake pads with aluminium cooling fins can reduce the brake pad surface temperature by another 50 degrees the result is high stopping power and practically no signs of fadingthey