Synthetic and leather uppers. Bellows tongue provides a secure fit, while keeping debris out. Abrasion resistant TPU heel bumper. GORE-TEX® lining will keep your feet cool and dry. Breathable mesh lining treated with Aegis® Antimicrobial solution. Ortholite® Anatomical Footbed for all day comfort. Heel features the Merrell air cushion, providing shock absorbency. Vibram® Siren Sole is durable, shock absorbent, and slip resistant. Lace up closure for an adjustable fit.