The Base Camp 200 Waterproof Boots feature 50/50 Insulation for temperature regulation, an PEVA shell for protection, and a high-traction Vibram® outsole. These boots are constructed with internal waterproof membranes and seam-sealed detailing. pull-on pu-coated material waterproof, seam-sealed construction internal peva shell 50/50 insulation™ injected peva shell midsole vibram® xs trek evo outsole