The N-Ferno 6818 Knit Winter Hat is made with 3M™ Thinsulate™ insulation and a soft fleece liner for comfortable warmth. The 100% stretchable Dralon acrylic shell makes for a snug, cozy fit that keeps cold out. Low-profile for wear alone or under hard hats. This winter hat is ideal for those working in construction, transportation, warehousing, refrigerated areas and more. Can also be worn for weekend activities such as hunting, climbing, running, cycling and skating.