DESCRIPTION:The Smartwool Merino 250 Base Layer One Piece is made of heavier fabric to keep you warm in cold weather. FEATURES:Interlock knit provides ultimate comfortFlatlock seam construction designed to eliminate chafingFront fly and zippered drop tail for no-fuss nature breaksClose-fit hood for ease of movement and under-helmet fitZip chest pocket and thumbholes at wrist21 inch center front zipper with semi-locking slider Slim Fit100% merino wool