Our best selling totally waterproof windproof and breathable knitted beanie hat suited to a multitude of outdoor uses could this be the most versatile hat on the market totally waterproof windproof and breathable acrylic knitted outer for maximum water repellancy close fitting knitted construction with improved fit micro fleece lining for warmth and moisture controlthermal rating 4correct sizing for this product issm 55 57cm lxl 58 61cm xxl 62 63cm