Outdoor enthusiasts who buy the Caribou generally keep it forever--or at least until the felt liner wears thin. That's why Sorel updated their timeless classic a decade ago with a removable (and replaceable) 9 mm. ThermoPlus® felt InnerBoot. It has an enhanced moisture-wicking four-layer construction that insulates while reflecting body heat back to your foot. The Caribou™ features a waterproof full grain leather upper that keeps rain snow and slush out of your socks. We love ours for après especially in the early winter or spring when village streets and parking lots run gray with oozing channels of slush. The streamlined Aerotrac™ outsole might look a little different from the heavy lug sole of classic Caribou™ boots but the claw-like grip remains the same especially on polished ice surfaces.