TheSwissStop Catalyst Rotors 6-Boltexceldue to extremely efficient thermal management, Catalyst provides notably shorter stopping distances with very low wear rates under hard braking, exceeding the current industry leaders. SwissStop Catalyst Rotors 6-Bolt Features Optimum heat dissipation for maximum braking endurance and shortest stopping distances Reliable performance from cyclocross to downhill High durability, even in the toughest conditions Lightweight 7075-T6 aluminium spider Highly efficient SUS410 stainless steel brake track UCI approved for use in road competition 6 bolt fitment 110-198g