**REMOVABLE INSOLE** 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 it’s all about cushioning and alignment, with proprietary Merrell Air Cushion matched to Q-Form® stride-centering.