Some products follow a short but intense cycle, and then disappear, others have always existed, and live shorter or longer periods of great form but remain constantly in the range of the most famous producers of sportswear. The cycling skin-suit or aero suits belong to the latter category and as such undergo constant refinement cycle that brought them now to be mostly preferred, in some cases, even to the classic clothing of cyclists on the road thanks to their unparalleled comfort and exceptional fit type "second skin". Needless to say, this is obviously meant for a well physically built "athletic" and standard sizes can reap the benefits without suffering the limitations of the aero suit. It also adds the refinement of the materials and the possibility of the use in water and in the running thanks to the freedom of movement of the arms - particularly in the case of the Castelli sleeveless speed-suit - it's easy to understand how they have become the head of the favourite clothing even in the triathlon and duathlon races.