The Castle X Women's Charge Atop Boot INSULATION: 3-Layer Merino Wool insulation with air mesh & perforated air trap foam. Castle ColdShield Technology: Removable insole engineered from wool with a metallic heat reflecting layer. WATERPROOFING: Fully integrated Castle DRY-X waterproof. Sizing Sizes range from US 6 to US 11. Performance Women's Charge Atop Boot has reflective materials and high abrasion toes for maximum visibility and durability. Construction The Women's Charge Atop Boot uses Castle DRY-X waterproofing membrane along with a 1000D nylon upper fabric and Armstrong PU coated leather for a dry riding experience! Function Women's Charge Atop features Atop system for a custom fit and quick release. This boot also sports an EVA foodbed for all day comfort and additional protection from the cold! Sizing Performance Construction Function Colorways Gray/Black Women's Charge Atop in colorway Gray/Black White/Black Women's Charge Atop in colorway White/Black