Bunny boots

These large, bulbous, waterproof rubber boots can be worn in extremely cold weather, −20 to −60 °F (−29 to −51 °C), with the liner-free interior retaining warmth by sandwiching up to one inch of wool and felt insulation between two vacuum-tight layers of rubber; this vacuum layer insulates the wearer's feet similar to a vacuum flask.

[1][citation needed] These boots were originally developed at the Navy Clothing and Textile Research Center in Natick, Massachusetts, for use during the Korean War.

[1] Owing to their warmth and low price, these boots have become staple extreme cold weather gear both in civilian work and recreational environments.

Given the sufferings of the soldiers fighting in the Battle of Chosin Reservoir in Korea, inducing many cases of frostbite, even with Type I boots, the Type II was created to encompass the "worst case scenario" need to field soldiers in the coldest conditions in which any military force could reasonably attempt to conduct operations (including Alaska, Siberia and both Arctic poles).

During the fall the hares' fur changes color from brown to white, allowing it to blend in with its winter surroundings.

They retained essential features such as multi-layered insulation and waterproof rubber exterior while advancing the use of modern materials and ergonomic improvements, such as a moisture-expulsion insole and more traction on the outsole.