Merrell Women's WaterPro Crystal Slip-On Shoes QForm technology provides the cushioning and support necessary to align a woman's stride. Molded nylon shank provides enhanced stability and great arch support. EVA midsole with Air Cushion centers the heel on impact for superior cushioning and stability. Synthetic leather / mesh upper, Etc. Anti-Friction upper lining treated with Aegis, EVA insole... Compression-molded EVA midsole with Air Cushion in heel, molded nylon shank, Vibram rubber outsole.