evo.com | Arc'teryx Long Underwear Tops > The Arc'teryx Rho Merino Wool Crew Neck Top delivers natural performance across multiple activities with its innovative 240gsm 18.5 Merino construction that wraps around a durable nylon core for exceptional longevity. Featuring body-mapped articulation that follows your movements during technical pursuits, this versatile base layer naturally regulates temperature and fights odor during multi-day adventures from alpine climbs to backcountry tours. Crew Collar Fitted Arc'teryx's trimmer fit is patterned to stay close to the body through the chest, waist, hip, and thigh. Its low profile eliminates bulk, moves with the body, and fits comfortably under outer layers. 240gsm Mountain Merino Wool 95% Wool / 5% Elastane Strategically Placed Seams Increase comfort and reduce chafing. Care Instructions Machine wash gentle medium. Tumble dry normal low. Do not bleach. Wash dark colors separately. Do not dry clean. Iron low. Do not use fabric softener. Use wool detergent. Remove immediately. Do not wring. | Arc'teryx Rho Wool Crew Neck Top Men's 2026 - X-Large Gray | Nylon/Wool/Elastane