Flaunt happy and stylish feet with the Vionic Serenity Slip On. The Orthaheel and Vionic technologies and natural alignment make this style a must-have. For support, balance, and stability, this casual slip-on features a biomechanical footbed, firm yet flexible midsole, and deep heel cup. Furthermore, the crisscross straps add subtle style to this pick. Vionic brand's biomechanical technology is shown to be an effective treatment for heel pain. Vionic brand's biomechanical footbed supports you from the ground up. By building biomechanical technology into premium footwear, Vionic brings together the best of science and style. For the greatest comfort, we recommend wearing your new Vionic footwear for just a few hours for the first few days to allow your feet to adjust to the new level of orthotic comfort and support. Within one to two weeks you should find the product completely comfortable and supportive. Vionic Technology Natural alignment Orthaheel Technology Crisscross straps APMA certified. Vionic Natural Alignment.