Timberland PRO Men's Thermal Force 9" Xl Thermal Safety Toe Work Boot 100% Full-grain leather and Fabric Synthetic sole Smartwool natural fiber lining, Efficiant 3M Thinsulate Zone non-quilted lofted insulation (600g/1000g) for warmth without bulk Thermal XL safety toe featuring an insulating ceramic coating for warmth Waterproof full grain leather with waterproof membrane Underfoot aluminized Mylar insole prevents heat loss from ground contact, Reflexion aluminized lining reflects heat back inside the boot for added warmth