Best Use: Base Layer Combining naturally odor resistant Nuyarn® Merino wool with a super-comfortable fit, the all-new ULTRA Merino 160 Bottom is purpose built for extended wear on your toughest hunting expeditions. It’s ideally worn on hunts when the zip-off feature found in our other base-layer bottoms is not needed. Solving the durability and stretching-out issues associated with typical men’s merino wool thermal bottoms, they maintain their shape without sacrificing a comfortable fit, while providing natural odor resistance.