The Prowool Freeze Turtle half zip base layer has hollow fibre technology & a warm Merino wool combination. The inner layer, inspired by the fur of a polar bear, features the unique hollow LIFA thermic tube technology that insulates & allows for superior evacuation of moisture. The outer one features super fine merino wool with zero itch-factor for added warmth. The base layer is top of the range promoting transport of comfort stealing moisture off the body & to the next layer, resulting in you feeling dry & able to perform better for longer. Wear the top with complete confidence that you will be comfortable & in-style all day, even in very cold temperatures its the base of good performance.