The Arcteryx Men's Pelion Comp SS Top is designed for those of you in it for the long haul. Combining two fabrics to give you the best of both worlds (the worlds Are thermal Performance and durability and the fabrics Are Merino wool and nylon). The Merino wool provides natural odor resistance and moisture wicking properties to keep you less stinky and drier than your trekking counterparts. Nylon reinforcements in the shoulders ensure that even the bulkiest of packs won?t destroy your shirt before you?re ready to change. The regular Fit and gusseted underarms give you plenty of room to perform on-the-trail cartwheels, if you?re into that. Features of the Arcteryx Men's Pelion Comp Short Sleeve Top Merino wool with a nylon core provides durable, long-wearing comfort, odour resistance and thermal management Woven nylon fabric in shoulders and sleeves adds abrasion resistance Gusseted underarms for mobility and freedom of movement Excellent for long-wearing comfort, odour resistance and thermal management Core-Spun Technology: Merino Wool engineered with a Nylon core for increased strength and durability Merrow stitch seam construction reduces seam size