Merrell Siren Sport Waterproof Outdoor Shoe features a Vibram® outsole fortified with 5mm lugs, the traction is completely reliable. Strobel construction offers flexibility and comfort. Synthetic leather and mesh upper. Bellows tongue keeps debris out. Waterproof membrane provides an impermeable but breathable barrier. Lining treated with Aegis® antimicrobial solution resists odor. Ortholite® anatomical footbed. Molded nylon arch shank. Merrell QForm® Comfort midsole provides women’s specific stride-sequenced cushioning. Merrell air cushion in the heel absorbs shock and adds stability. 5 mm sole lug depth. Vibram® Siren Song Sole/TC5+ Rubber.