It was castelli pro riders who first requested a garment that wasnt as hot as the gabba but was warmer than the perfetto vest so with the gabba as a starting point castelli construct the back in nano light fabric the same fabric as their nano flex tights but without the brushed fleece inside this gives the piece a lot of breathability and keeps you from overheating inside by using a lighter weight of windstopperreg a full 25 lighter than the one used on the gabba on the fron