Removable Active-Fit multi-layer inner boot system; B-Tek Heat lightweight, 4-channel hollow-fibre insulation for high-loft breathability in a broad range of temperatures; B-Tek Lite proprietary aero-insulation blend that allows the inner boot to achieve greater thermal regulation while using less material; Thermawick comfortable, hi-wick next-to-foot lining material for greater breathability and improved thermal regulation; B-Tek Dry Waterproof Base; Stylist leather and nylon upper with pull loop at the back for ease of entry; Hiker heigh shaft for improved agility; Superlite Blend compound shell for a lightweight performance fit; LiteGrip Blend base for lightweight cushioning and grip; Polar Rubber outsole for maximized grip and longevity of boot at cold temperatures