100% Acrylic Heat Holders Yarn – Specially developed thermal yarn provides high performance insulation against cold. It also has superior moisture breathing abilities. 3.6 Tog Rating – The tog rating is a measurement for the thermal ability of a garment. 3.4 tog is considered to have very high thermal ability. Heat Weaving Lining – Heat Weaver insulation is a plush fur-like thermal lining that maximises the amount of warm air held close to the skin. Ribbed Design – The ribbed design of these winter hats makes sure the hat is secure and keeps to your head for maximum comfort. Turn Over Style – Even with warmth, style is needed. This turn over hat is super comfortable.