Merrell Men's Mix Master Mid Waterproof 100% Synthetic and mesh Rubber sole Waterproof Membrane - Provides impermeable but breathable barrier for protection against the element. Fabric Upper - With EZ Clean finish to shed dirt and resist stains. TPU Overlay - Provides a secure fit and snug fit along with foot support. Air Mesh Bellows Tongue - Keeps debris out of the shoe for a more comfortable experience. Merrell Float Midsole - 10% thinner and 25% lighter to provide more feel and ground control.