Orthaheel Dr. Weil Calm Thong Sandals Synthetic Built-in Biomechanical Orthotic Arch Support - Orthaheel technology properly aligns your feet with you lower limbs - impoves balance- posture and foot comfort. The Calm has soft- premium full-grain leather straps and a comfortable toe-post. Comfortable microfiber-covered EVA footbed gives you additional cushioning on top of the arch support. Durable rubber outsole. Medium Width AMS - Aided Motion System - combines innovative and tested technologies that will take you where you want to go- balanced- energized- and in comfort.