HOW DOES IT WORK? outer and inner diameter of the disk have a non-round design that enables better radial expansion of the rotor under extreme heat conditions. Moreover piercing holes are replacd by edges specifically designed to grow brake pad regeneration process CHARACTERISTICS > BENEFITS more braking grip > highly reactive less weight > better handling high heat dissipation > stable power at all conditions Compatible with: - Mbk: Booster 50 euro 0-1_S, Nitro 50_S, Stunt 50 euro 2_S - Yamaha: AEROX 50_S, neo's 50_S