The XTR RT-MT900 Ice Tech rotors provide consistent braking performance through heat energy control using a revolutionary stainless steel & alloy 3-layer sandwich construction. This rotor construction technology allows heat generated from braking to radiate quickly through the aluminum core achieving braking surface temperature drops of around 50 deg C or more when used with Ice Tech pads. These rotors build on the success of previous Ice Tec technology with the new Shimano Freeza design, this allows the alloy core to extend out from the braking surface as a fin to providing additional cooling.