Smartwool Training Headband 100% Wool 45% Nylon 39% Merino Wool 16% Elastane. One size fits most. Washer and dryer friendly! HyFi terry back knit construction with clean finish seams for a snug, comfortable fit. Contoured, double layer drop-ear headband with terry loop interior knit for comfort and warmth. Washer and dryer friendly!