The key difference between Craft's Active and Active Extreme base layers is that the latter takes less than eight minutes to go from wet to bone dry. When you're playing in conditions as low as 10 degrees Fahrenheit, extra minutes can have serious consequences. The Active Extreme WS Top Base Layer, with the addition of Gore's venerable Windstopper material, ups the ante further by making the front panel literally windproof. The non Windstopper portions are made of a blend of six channeled and hollow core synthetics for three reasons. The hollow core provides merino esque insulation by creating pockets of warm air between you and the elements, the six channeled fabrics increase effective surface area for better moisture management, and they're super stretchy. Flatlock seams hold it all together to eliminate chafing. The Women's Craft Active Extreme WS Top Base Layer is available in five sizes ranging from Small to XX Large in the color Blackplatinum.