Only fits the models with the detachable collar. For the F83 E PRO - F83 E XGi - PRO - F83 EVO PRO - F83 EVO XGi PRO models with the 83 mm burr set. Called the "PORTA MACINA FISSA F83 CAMERA ESTRAIBILE COMPLETA DI FLANGIA" or fixed bur holder for the F83 removable chamber complete with flange.