The Icebreaker M Merino 200 Realfleece Descender LS Zip H is a merino mid layer specially developed for high intensity activities in cool weather. The Realfleece fabric blend of Tencel Lyocell and merino wool provides optimal warmth and softness, while the material is breathable and odor-resistant. Cool-Lite eyelet mesh inserts under the arms provide improved ventilation during movement. The Descender also features a hidden chest pocket for small essentials and flatlock seams to prevent chafing. Absolute naturalness is guaranteed by the plastic-free fibers.