SottoZero multi-denier 100% polyester fleece fabric. Flat-lock stitching. Mesh armpit insert. Higher than normal neck can be pulled up to act as a neck warmer.
Another piece that started in a Team Sky focus group – our warmest base layer (Flanders) with essentially a built-in neck warmer.
On merely cold days, keep the neck down to fill in the space inside the collar of your jacket.
On brutally cold days, pull it up over your face for extra warmth, with the double layer SottoZero fleece fabric to keep you even warmer.