Non-standard stainless steel brake disk bolt, 20mm long for V11 Sport 1999-2001, California Special Bassa 1999-2000, 1100 Sport Injected 1996-1999, California EV 1998-2000, V10 Centauro, Daytona RS 1997-1998. 1100 Sport Corsa 1998-1999.
Always use an anti-seize compound on stainless fasteners.
Note: parts books show both 20mm and 25mm bolts for the front brake on some models. It's best to replace the bolts with the same length that you removed so order accordingly.