The TRP 42 disc rotor is designed specifically for use with select TRP DHR and E-MTB brakes. Its two-piece design offers heat management and stiffness. Offer a lower temperature under braking 50% reduction in rotor warping/deformation compared to a standard rotor Six slots to remove water, mud, and debris 2.3mm rotor thickness If your new rotors are a different size than the ones you&';re replacing, then you&';ll need new brake adapters! Check out our guide to getting the right brake adapters to spend less time on the computer and more on the trails.