Fully functional for warmth ventilation and support while alpine climbing backcountry skiing or other day long adventures in the wild the body features 260gm merino wool fabric with a touch of lycra174 for stretch in the gusset icebreaker have used lightweight 180gm eyelet merino mesh that actively controls temperature during high output pursuits and in the higher wear areas around the knees they39ve added 230gm merino and polyester waffle jersey for added abrasion resistance flat