The Sportful BodyFit Pro Short Sleeve Baselayer is made from a ribbed fabric allowing for greater thermal regulation helping your body stay comfortable on those cold days on the bikes. The fabric features lightweight rows alternating with three-dimensional rows to help trap air while allowing your body to breathe. The crew-neck provides extra comfort and warmth and helps prevent any cool air get between you and your jersey. Key Features Short Sleeve crew-neck base layer in ribbed polyester fabric ,Simple construction and seaming.