Explorer wool long johns are made from the same material as in the Combo jacket. It is suitable for cold days, over thin long johns and under wind pants. The Explorer is not elastic. It fits snugly and is very warm. Should be used with thinner long johns underneath if you have sensitive skin. Color: Charcoal. Comes in 4 sizes: XS/S, M/L, XL/2XL, and 3XL/4XL.