Featuring a polyester mesh inner for its wicking properties, the outer layer is 100% merino wool. It even arrives with a woolmark tag to prove it. Fitting very neatly & subtly under a helmet, the merino flat cap is the ideal alternative for those who feel the more regular casquette is not for them. Worth bragging about over a cappuccino Helmet compatible fit Silky, itch-free comfort Naturally odour resistant Wicking mesh liner High warmth to weight ratio even when wet Easycare machine wash