Duck hunters first recognized this waterproof boot for the warmth is provides with the 8mm removable felt liner rated to minus 40. Tuck your pants inside the shaft and tighten the drawstring collar to keep out the cold air and any burrs or twigs from annoying your leg. It has now become an all-purpose boot that just slips on and protects you from cold rain, slush and snow or wherever your venture or chores take you.