The SM-RT900 brake rotor was designed by Shimano especially for Dura Ace BR-R9170 disc brakes, but it's also compatible with other flat-mount as well as MTB brakes.
The enlarged adapter between the brake surface and the cooling plates improves the heat dissipation from the rotor surface by a further 40° C in comparison with Ice Tech brake rotors.
SHIMANO’s ICE TECHNOLOGIES has realized the ultimate rotor, incorporating aluminum fins for enhanced heat control. With an increased surface area for heat dispersion, the rotor achieves a 50°C reduction in heat. This in turn generates a 20% increase in braking force durability and a 20% longer pad life.