Designed with the groundbreaking 'Sure Tread' deep-cleated outsole, the Stream II continues to lead the way in the premium wellington category. Its adjustable rear calf strap ensures a sleek and confident side profile. Waterproof rubber upper 3.5mm insulated, Neoprene lining Adjustable rear calf fitting Internal structured heel support Rubber kicker Rubber 'Sure-Trend' deep cleated sole Padded, removable insole Unisex sizing As the first boot built around the 'Sure Tread' deep cleated outsole, Stream II remains a trailblazer in the premium wellington category. The adjustable rear calf strap offers a clean and assured side profile. Upper: Rubber Lining& Sock: Neoprene Sole: Rubber As the first boot built around the 'Sure Tread' deep cleated outsole, Stream II remains a trailblazer in the premium wellington category. The adjustable rear calf strap offers a clean and assured side profile.