Fast forward, fast upward: With the 120 MERINO COOL TEC line, you'll be prepared for any heights. The lightweight FAST UPWARD TOP for women has an athletic cut for full freedom of movement when climbing and mountaineering, and thus completes our line for warm days. The material mix stands for pure functionality: The combination of fine merino fibers and Tencel TM cellulose fibers of botanic origin is self-cooling, tough and durable thanks to corespun technology. This is due to a complicated process in which the fine merino and Tencel TM fibers are spun around a core of polyamide filaments. The resulting yarn is used to produce a material that has the same benefits as merino wool and Tencel TM , and is even more robust.