Northwave extreme pro high socksthese extreme pro high socks from northwave are made of primaloft silver performance yarn with a merino wool blend that combines superior insulated warmth with quick drying properties in an ultra fine yarn lightweight added comfortthey are lightweight weighing only 38g and have 25cm cuffs to keep the calves warm these pro socks also have double elastic ribbed tops to prevent slippage and reinforced towelling soles for durability and added comfort featuresmain