Constructed with 7mm Neo-Tech waterproof insulation. BOGS Max-Wick evaporates sweat to keep feet dry. Self-cleaning outsole BLOOM eco-friendly, algae-based EVA footbed that helps clean polluted water habitats. 100% Waterproof. Comfort rated to -40°F/-40°C. DuraFresh natural bio-technology activates to fight odors. Durable, hand-lasted rubber with a four-way stretch inner bootie. 90° heel for support on rough uneven terrain.