Merrell Siren Sport A Siren that sounds the alarm when the weather comes up bad, and keeps pace with the worst it can throw out. Mesh upper backed by GORE-TEX® membrane has the highest level of breathability while being completely waterproof without any unwanted bulk-up. Narrow gauge webbing and synthetic leather strapping provide support while anchoring speed lacing. Underneath its all about cushioning and alignment, with proprietary Merrell® Air Cushion matched to QForm® stride-centering. UPPER/LINING Strobel construction offers flexibility and comfort Synthetic leather and mesh upper Bellows tongue keeps debris out GORE-TEX® Extended Comfort Footwear lining keeps feet dry and comfortable Lining treated with Aegis® Antimicrobial solution maintains foot comfort Ortholite® Anatomical Footbed MIDSOLE/OUTSOLE Molded nylon arch shank QForm® Comfort midsole provides womens 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 Weight: 11.5oz (326g)