Castelli womens flanders long sleeve base layerthis womens flanders long sleeve base layer is made from a high loft fleece on the inside which provides warmth to spare the softness on your skin is a nice touch with the excellent moisture management of this 100 multi denier fabric its stretchy for a perfect fit and the flat lock seams add quality castelli has used two different weights of fabric with the thin layer covered by your shortstights so you dont have too much insulation where