The Vionic Gerrit Sandal was designed for a little adventure and a lot of support. It offers maximum customization and ultimate comfort through three points of hook-and-loop adjustability. Flexible upper featuring fully adjustable hook-and-loop straps and soft, padded jersey liner Embossed EVA footbed absorbs shock, reducing stress on feet, ankles, and knees Durable rubber outsole with flex grooves for improved traction Innovative podiatrist-designed Orthaheel Technology provides superior orthotic support, relief and stability which helps realign the feet back to their natural position Research supports Orthaheel Technology's success in reducing over-pronation, which can help relieve associated common aches and pains, such as heel pain (plantar fasciitis), knee pain and lower back pain. 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 Natural Alignment.