Strobel construction offers flexibility and comfort. The waterproof suede upper and waterproof membrane provide an impermeable but breathable barrier. This comfy shoe features 200 grams Merrell Opti-Warm lightweight, low-bulk, insulation that keeps you warm. There's an EVA removable footbed treated with Aegis antimicrobial solution. It has a molded nylon arch shank, a Merrell air cushion in the heel that absorbs shock and adds stability with an EVA midsole for cushioning.