Paddy, the discs are basic 330 mm ( or whatever the size is Brembos, but for the F40, as they have CAST holes in them ,these really are pukka bits, as they have floating discs & the bells ).
the whole lot was a TI special, the quality from the firm that made them was top notch, however one minor thing is that the outer pads have to have 2 - 3mm of the outer edge cut away, as it otherwise clashes with the rotor, not big issue, as i did them at work & then repainted, but the stopping even on OEM Alfa pads is quite something & NO SQUEAL ever