With a gusseted crotch and comfortable elastic waistband, the Sitka Core Midweight Bottom offers just enough warmth for chilly fall days without making you sweat. Permanent Polygiene Odor Control Technology neutralizes odor by stopping the growth of odor-causing bacteria and fungi. The CORE Midweight Series is the foundation for your cool weather system, with a micro grid fleece backer that lightly insulates while actively moving moisture away from the skin.