Earth - Traveler (Black Butter Calf) - Women's: Walk through your journeys in comfort and style with the 'Traveler' slip-on. Soft, calfskin upper features dual instep goring for flexibility and fit. Leather lined, anatomic footbed with shock absorbing Gelron2000(R). 'Traveler' is airport friendly too!; Earth(R) features unique Negative Heel(R) Technology, which is the product of years or research by a celebrated Danish Yoga teacher, Anne Kalso(R). 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.