SHIMANO RT-EM910 disc brake rotors for speed sensor systems deliver powerful and consistent brake performance in all riding conditions. The compact and lightweight ICE TECHNOLOGIES FREEZA rotor significantly reduces heat build-up in the brake system to ensure consistent high performance braking even on the steepest downhill stretches. SHIMANO's CENTER LOCK mounting system makes installing and removing rotors quick and easy thanks to the spine mount and lock ring design.Compact, clean, and low profile designEasy installation to the rear wheelSuper high heat dissipation by black painted radiator finLightweightNarrow type disc brake rotorRecommended brake kit: M9120/M8120Weight: 144 g (180 mm)Alloy lock ring CENTER LOCK ICE TECHNOLOGIES Outside diameter: 203 mm (For rear only with magnet bracket)Brake pad compatibility: Metal, ResinICE TECHNOLOGIES FREEZA