The Terramar Men's Base Layer Long Sleeve Crew Neck Top is the ideal top for all day warmth and comfort, while being out in the elements. This versatile base layer crew neck features an ultra-soft, mid-weight fabric, utilizing ClimaSense Thermoregulation Technology that automatically adjusts to your body temperature. The fabric traps air to maintain warmth, when your body starts to cool down. And, when your aerobic activity increases and your skin temperature rises, the fabric allows moisture vapor to escape, to maintain your comfort level. The Crew Neck Top has functional thumbholes, and strategically placed mesh panels for warmth and breathability. And, the Terramar top's 4-way stretch fabric moves naturally with your body in all activities, while the odor control neutralizes sweat and odor during wear.