It’s a bracket that makes sense. With a simplified approach to hardware, only mounting bolts are required, and for the best possible rotor to caliper alignment, two size-specific brackets cover the four common rotor size combinations. Maven calipers require this adapter for 20mm jumps Includes mounting bolts Stainless steel hardware No CPS (concave/onvex) hardware required +20mm P-1 Adapter for 160mm and 180mm rotors +20mm P-2 Adapter for for 200mm and 220mm rotors