Castelli prosecco sleeveless base layercastellis prosecco sleeveless base layer is made for cool conditions or even high intensity cold rides where wicking moisture away from your skin is key the hydrophilic prosecco treatment spreads the moisture out over a larger area for quicker evaporation castelli has used two different weights of fabric with the thin layer covered by your shortstights so that you dont have too much insulation where its not needed featuresexcellent moisture managemen