Keen - Growler (Charcoal) - Men's: Leather upper that repels water and will not breakdown. Moisture-wicking fabric lining that keeps water out of the boot. PrimaLoft 200g insulation that's comfort rated to keep feet warm in -20 F temperature. Keen patented toe protection with additional insulation provided by the EVA midsole and rubber. Molded Tuff Tech heel offers added protection including lugs for grip for kicking the boots off after a long day in extreme weather conditions. Directional lug "Dual Climate Rubber" outsole adjusts for the best traction by hardening in cold temperatures and softening in warm temperatures.