Shim Ring (Shim Washer) Stainless Steel 6-piece Set, Inner Diameter M8 (8 mm + 0.3 ) x Outer Diameter 0.6 inch (16 mm) x Thickness 0.01 inch (0.3 mm) BREMBO / NISSIN and other rear calipers such as BREMBO / NISSIN, this set is for adjusting the mounting position of the caliper to the center of the disc rotor. Shim Ring SUS304 M8 x D16mm x T0.3mm