The Snowgem winter boots feature a seam-sealed, waterproof construction that keeps your feet dry thanks to the 3M Thinsulate insulation, and they are also made from eco-friendly Litem leather. Whether you're shoveling your car out or snowshoeing with the family, the removable comfort insoles with odor control ensure you stay comfortable. The more air a material holds in a given space, the higher its insulation value. The microfibers in the Thinsulate insulation are much finer than other fibers, allowing them to "trap" more air in less space, providing excellent insulation.