Fox Fire Alpha Jacket Warm, fleece-lined mountain bike jacket for cold rides. When the temps drop on the trail, the Defend Fire Alpha Jacket is the perfect go-to for bringing the heat back. With its strategically placed Polartec Alpha fleece lining, the jacket is designed to keep you insulated while you ride, and all without overheating. The bonded cuffs of the jacket are an added defense against the cold, while the stretch Cordura material used in the shell provides increased abrasion resistance and maximum mobility. Stay warm as you shred with the fleece-lined Defend Fire Alpha Jacket. Strategically placed Polartec Alpha lining keeps you insulated, all without overheating. Stretch Cordura material for increased abrasion resistance and maximum mobility. Bonded cuff closures with lycra gussets to keep the cold out. Rear zippered pocket for additional storage. Shell: 74% polyamide nylon, 18% polyester, 8% elastane. Lining: 100% polyester.