Soft nylon three-way adjustable straps and a deep heel cup provide a secure fit. The flexible traction soles and built-in arch support keep you on the move in comfort on various surfaces. Feel confident and comfortable on any terrain in this adventure sandal! Earth features unique Negative Heel Technology, which is the product of years or research by a celebrated Danish Yoga teacher, Anne Kalso. Anne Kalso discovered that positioning the heels below the toes naturally aligns the body, just like the Yoga Mountain pose. This natural posture and alignment relieves fatigue for people who are on their feet all day. Vegan Certified.