Volcanic Mud Ski Base Layer for Ultimate Warmth and Comfort The Volcanic Mud Ski Base Layer features a built-in heat-trapping system to provide exceptional warmth against the cold. Constructed with seamless knitting technology, it offers a comfortable fit that minimizes chafing during movement. Its zoned compression design targets the specific needs of different muscle groups. Made with high-performance volcanic mud yarn, it ensures dynamic warmth regulation—keeping you warm even when you sweat, and effectively reducing dampness and chill.