Removable Comfort-Fit multi-layer inner boot system; Double B-Tek Heat lightweight, 4-channel hollow-fibre insulation for high-loft breathability in a broad range of temperatures; Thermaplush soft, next-to-foot wicking layer for warmth; B-Tek Dry Waterproof Base; Snowshoe Compatible; Double-strap Velcro for easy fastening and added security; Nylon locking snow collar with built-in extendable gaiter to protect from the elements; Arctic Rubber shell to provide lightweight flexibility, cold-resistance and resilience; EVA midsole for light-weight insulation and cushioning; Polar Rubber outsole for maximized grip and longevity of boot at cold temperatures