Size 13 QUATRO KNEE 16" The next generation in waterproof footwear. Hand-built using natural rubber formulations developed to meet our exacting quality standards, Quatro provides the highest level in comfort and durability. Knee height fully clad, UV resistant natural rubber boot with anti bacterial moisture wicking lining, 4mm CR-Foam insulation and a 4mm insulator wool-felt base. Ergonomically designed to support the foot and prevent heel slip. Podiatrist-inspired Quatro Comfort System Innersole. High abrasion, cupped rubber outsole designed to cushion and spread load.