The FI.13_S5 shorts have A430 side panels for compression and venting, and harder and less elastic inner thigh sections designed to keep the ‘revolutionary’ chamois in place.
The chamois feels like a combination of a bath sponge and cotton wool, which you can twist in every direction. In use, it keeps a low proﬁle and provides one of the comﬁest rides imaginable.
The back of the bib strap is web-like for breathability, and the front has Assos' ABC-M closure mechanism. That turned out to be the weakest link in this package, and kept unclipping.