The PowerSocks Heat Fusion Outdoor heated socks are the ideal choice for all winter outdoor activities. Technical, soft and breathable, they truly wick away moisture thanks to their specific microchannel construction. They are made of Merino wool and provide maximum comfort on the sensitive areas of the foot, namely the shin, calf and instep. The Fusion heating system heats from both the bottom and top in the toe area, providing maximum thermal comfort in the most sensitive area of the feet. The PowerSocks Heat Fusion Outdoor heated socks are the warmest socks in the Therm-ic collection. They are the perfect heated socks for hikers, hunters and fishermen. The socks are sold without batteries. Find all compatible batteries by clicking here. Three heat levels are available, to adapt the heat to your needs. Technical features Quick and easy battery fastening thanks to snap fasteners Heel and toe reinforcement: maximum comfort for all outdoor and mountain activities Heat Fusion Technology: even heat distribution around the toes and under the forefoot CARE INSTRUCTIONS Remove the batteries before washing the socks Turn the sock inside out before washing Wash the socks in the washing machine at 30 maximum with a low spin Do not use bleach Do not use fabric softener