Engineered 3D Warmth and Comfort. Xcel’s Drylock Boot has been updated with a sleeker design and reduced bulk. This 3-dimensional boot contours to the foot while minimizing excess rubber on the sole, providing a true board feel. The new Thermo Dry Inferno (TDI) interior and Channel Flex exterior make it extremely warm and comfortable. A Drylock Cuff opening prevents flushing, while the ergonomic strap keeps your heel locked in and relieves pressure from the instep. A heel strap also makes for easy pull-on. The new Thermo Dry Inferno (TDI) interior and Channel Flex exterior make it extremely warm and comfortable. • Channel Flex• Thermo Dry Inferno (TDI)• 3D Design• Drylock Ankle Seal• Pull Up Heel Loop• Ergonomic Strap• Fusion X Seam Tape The all new Drylock boot is the most trusted boot in the water.