KEEN Men's Revel IV High Polar Waterproof Insulated BootBrave the from frozen trails or city streets in the insulated Revel Winter Boot Waterproof leather and performance mesh upper sourced from LWG rated tanneries Non marking 5mm multi directional lugged outsole with KEEN. POLAR Traction for better grip on ice and snow 400g of KEEN. WARM Recycled P. E. T. insulation rated to 40F 40C Thermal Heat Shield insole with a thermal foil barrier to keep the cold out and heat in bay harnessing radiant heat Heat