With lofted insulation and articulated patterning, The CORE Heavyweight Bottom in Optifade Elevated II keeps your lower limbs snug during long periods of frigid inactivity. Permanent Polygiene® Odor Control Technology neutralizes odor by stopping the growth of odor-causing bacteria and fungi. The Sitka Gear CORE Heavyweight Series is the next-to-skin foundation for static hunts in cold weather, with a lofted grid fleece backer that retains warmth while actively moving moisture away from the skin.