Inspired by our athletes with a thirst for lighter, faster-climbing gear, the Advanced Mountain Kit is the most sophisticated alpine climbing system we've ever created. This active base layer works with you as you climb. It harnesses Dot Fleece technology that pulls moisture from the skin and expelling it to the outside with the use of hydrophobic inner yarns and hydrophilic outer yarns, helping to maintain an even body temperature. The elevated back neck height provides extra warmth and protection.