With the aim of preventing heat-induced deformation, Shimano has reinforced the alloy carrier and optimized the arm shape in the RT-CL800 brake disc. The result is not only a smoother, but also quieter braking experience. With the help of the proven Ice-Technologies Freeza design, the disc at the level of the GRX RX810 series provides first-class, consistently stable braking performance even on long and steep descents. The key to outstanding braking performance is rapid heat dissipation, which is achieved with the help of the so-called sandwich construction (stainless steel - aluminum - stainless steel). This results in a significantly lower surface temperature, which in turn ensures less fading, a more consistent brake modulation as well as higher braking power, while at the same time less brake noise and a longer life of the brake pads. Feature: Highlights of the Shimano RT-CL800 brake disc reliable, smooth and quiet braking performance excellent heat dissipation for first-class braking performance on long, steep descents Ice-Tech Freeza design sandwich construction (stainless steel - aluminum - stainless steel) Centerlock mount ***These are OEM Shimano Parts, Brand new, Never Installed on Bike, Never used in any way, just NOT in retail packaging.***