Featuring a full grain leather upper and Merrell's women specific EVA midsole, the Opal from Merrell adds a fresh approach to exploring the world. Merrell Q Form Technology Video. QForm EVA midsole for stability, shock absorbing cushion, and a balanced stride. Supportive molded nylon arch shank allows forefoot flexibility. Full grain leather upper for durability and support. Vibram TC5 rubber outsole with 5 mm lug depth for traction and grip. Air Cushion in the heel absorbs shock and adds stability. Recycled mesh lining with Aegis antimicrobial solution helps eliminates odor. OrthoLite anatomical footbeds add cushion, wick moisture, and inhibit odor. Stroebel construction offers flexibility and comfort. QForm Comfort midsole provides women specific stride sequenced cushioning.