OMP profides perfect brakes for the 33, the number you see in the picture is the OMP product number (TFE/AL4010S)  for ordering these discs for the 33 16v or series 2 QV
 

 
When upgrading to these OMP discs (composed of durable metal and carbon) you must also upgrade your brake pads, these discs will eat your Alfa pads in a blink of an eye. I used pads from Ferodo, for the best result also change your rubber brake hoses for steel ebroided metal ones (makes the pedal feel firmer). Sorry for the poor picture quality.