Simms Waderwick Core Bottom, Layering for the long haul, formulated for all-season comfortBetween your skin and advanced outerwear, Simms' new Waderwick Core Bottoms optimize comfort thanks to double-knit fabric that mechanically wicks moisture. Four-season performance stems from COR3 qualities such as an odor-killing anti-odor treatment. Two-way mechanical-stretch-knit fabric improves mobility over previous-generation Waderwick Core fabrics.