Built using the same performance engineering that was used to developed Hyperflex Cryo Winter Boot. The Vyrl 5mm boot uses the same materials used in the Hyperflex Vyrl suits series. Featuring a new strain of Quantum Foam neoprene which is ultra-light weight, and feverishly warm. 100% lined with Fire Fleece the same heat retaining lining used in the 5/4 winter suits. Quantum Foam neoprene and Fire Fleece provides ridiculous stretch, extended mobility and superior comfort while at the same time, all but eliminating cold water movement through the boot.Less ThanBrGreater ThanLess ThanBrGreater ThanFusion welded seams, dual axis instep strap allows for maximum torque and comfort adjustments and integrated multi-layer sole, heal and toe layers are vulcanized as a unit to provide maximum support while not compromising flexibility. Wide finger loop above heel for easy on and off. Locking internal skin entry cuffs add warmth and comfort. Square toe box design with internal split toe to avoid snagged leashes. The Hyperflex Vyrl Split Toe 5mm Boot is black in color and is available in multiple sizes.