Bunny boots is the widely used nickname for the Extreme Cold Vapor Barrier Boots (Type II) used by the United States armed forces. The linerless bulbous boots retain warmth by sandwiching up to one inch of wool and felt insulation between two layers of rubber and are typically worn with one heavy wool sock. These boots were originally developed at the Navy Clothing and Textile Research Center in Natick, Massachusetts, US, for use during the Korean War.
Originally designed for the military, such boots have become staple cold weather gear both in civilian work and recreational environments. Bunny boots are very popular in Alaska.
Bunny boots Wikipedia
The black pairs, sometimes called Mickey Mouse boots, weigh 44 oz. (1.25 kg) apiece and are rated for temperatures down to −20 °F (−28.9 °C) and are made with oil/diesel resistant rubber. They are less common than the white pairs that give the boots their name.
The white boot is designed for use in extreme cold weather from −65 °F (−53.8 °C). It also is a little bigger and heavier (~8 oz. (0.22 kg) more per boot) than the black boot because of the extra insulation.
Both Mickey Mouse boots and bunny boots have an air valve on each of the boots. These air valves must be opened prior to flying, to ensure that the air pressure differential between the walls of the boot and the outside air does not cause the boots to rupture. A common theory on the origins of the name of bunny boots is that they make wearer's feet look disproportionately large, like Bugs Bunny's. The extreme cold weather boot is actually nicknamed after the snowshoe hare, commonly found near Ft. Greely, Alaska. During the fall the rabbits' fur changes color from brown to white, allowing it to blend in with its winter surroundings. As winter gets closer, more and more rabbits appear with their new white "boots". These boots are manufactured by several companies including Bata, Acton and Air Boss.
Both Mickey Mouse boots and bunny boots have rubber wedges on the front of the toe and the back of the heel. These wedges lock into military-standard ski and snowshoe bindings.