These foliage green (designed to match the color of the Army Combat Uniform or ACU) silk-weight thermal long underwear shirts are an excellent base layer to wear under your uniform, a sweater, ski attire, snow board gear, or work clothes. Modeled on the third generation of the military's extended cold weather clothing system (ECWCS) these Level I thermals are like those that keep our soldiers warm when they are on duty, so you know they'll be great for your outdoor activities.

These are made from a technical fabric that is superior to traditional "long john" cotton thermals, in part because the material is much thinner and lighter but also because they will not hold perspiration against your skin and cause you to get chilled. These are lightweight yet warm, highly breathable, moisture wicking, and have anti-microbial and anti-odor properties. This makes them ideal for use during strenuous activities in cool or cold weather that generate body heat and the potential for perspiration.

These thermals have a long tail designed to stay tucked in during aggressive movements, thumbhole sleeves so you can prevent them from crawling up your arms, and come in men's sizes S up to 3XL.

This listing is for the shirt or top only. Matching pants are sold separately.