Merrell Women's Siren Sport Gore Leather Strobel Construction - Offers flexibility and ultimate comfort. Synthetic leather and mesh upper - for good flexibility and breathability Bellows Tongue Cover - Protection from mud and debris from getting inside the shoe. Ortholite anatomical footbed - Combines a specific ortholite foam and Air cushioning to help improve comfort and fit. GORE-TEX Extended Comfort Footwear lining - Keeps your feet dry from the outside as well as from the inside.