Merrell - Hydro Next Gen sneakers Men Merrell Merrell at Simons Meet the Hydro Next Gen. The Hydro style you've come to love plus the performance capabilities from the brand that makes the world's #1 hiking boot brings you the most capable Hydro Moc to date. Equipped with max cushioning and an added rubber outsole for traction and durability, this performance slip-on is unrivaled. Breathable technical mesh upper with heat-sealed details and TPU heel 100% recycled straps, laces, lining and footbed cover Durable and lightweight FloatPro midsole containing 10% of BLOOM®/ foam made from algae biomass harvested from freshwater sources Durable rubber traction sole Model number: J85863