Brake disc adapter flange Moto Guzzi 320mm V65TT/NTX V35TT/NTX V75NTX. The disc is the same one fitted on Breva 750 V7 and more common models, both Brembo and Grimeca produce it. To match the flange you will need to fit a caliper moving plate.
 the flange is made of T6 ergal aluminum which is as resistant as steel but very light