The Bridgedale Explorer Heavyweight Merino Endurance Boot Sock is engineered for serious mountain adventurers and winter expeditions. Designed to sit comfortably above the ankle, it’s ideal for boots with extended cuffs and provides full cushioning for warmth and impact protection. Featuring Merino Performance Fusion Technology, this sock blends Merino wool with synthetic fibres to deliver outstanding moisture control, insulation, and long-term durability. Whether you’re trekking high-altitude routes or navigating extreme cold, this sock is tested and proven in some of the harshest climates on Earth. Advanced support zones, including a 3D-shaped heel cup, Elasticated Arch, and zonal padding system, provide a secure, blister-free fit that stays in place all day. The insulated Flat Toe Seam eliminates cold spots, while the Thermo Fit process ensures the sock retains its shape and size after every wash. Key Features: Heavyweight design for cold climates and multiday expeditions Merino Performance Fusion Technology for warmth, durability & wicking Engineered zonal padding for comfort and support Flat Toe Seam to reduce friction and prevent cold spots Elasticated arch & 3D heel cup for secure, locked-in fit Lycra® construction with Thermo Fit for shape retention Fibre Contents: 28% Merino Wool 19% New Wool 34% Nylon / Polyamide 18% Endurofil™ / Polypropylene 1% LYCRA® / Elastane