The 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. Track Page Views With Auctiva's FREE Counte. The item "Sitka Core Heavyweight Thermal Bottoms" is in sale since Saturday, February 27, 2021. This item is in the category "Sporting Goods\Hunting\Clothing, Shoes & Accessories\Other Hunting Clothing & Accs".The seller is "swillingtonshootingsupplies" and is located in leeds, West Yorkshire. This item can be shipped to United States, Canada, United Kingdom, Germany, Japan, France, Australia.