This is the needed part to convert a center lock rear hub to set the hub up to use a disc rotor and disc brake set up.
Center lock hubs bracket compatible
ISO 6-bolt disc brake rotors compatible
Size : 52x52x9mm / 2.05″x2.05″x0.35″
Weight : 27 g / 0.95 oz
Max torque : 30NM
The center distance between the ISO disc rotor and the hole is 44mm