O FIT Insole Thermal B-DRY Waterproof Leather/Synthetic Upper Swiftcurrent Outsole Winterized 3M Thinsulate Insulation There are winter boots, and then there are boots for being outside in the winter. Our insulated Sapphire is the outside kind of boot, built on a women’s-specific last. Waterproof nubuck leather combines with B-DRY waterproofing, 3M Thinsulate Insulation, an O FIT Insole Thermal insole,and a winterized rubber outsole for solid cold-weather traction. The end result is a warm, dry, and uncompromising winter hiking boot that gets downtown in style.