Merrell Women's Avian Light Ventilator Leather Strobel Construction - Offers flexibility and ultimate comfort. Breathable Mesh Lining - Treated with Aegis Antimicrobial solution maintains foot comfort. 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. Compression Moulded EVA footframe - for stability, comfort and cushioning under the foot.