BEFORE PURCHASING please view our newest sizing chart (second image). Size Extra Small fits Big Kids shoe sizes 2.5-4.5 and Women’s shoe size 4-6. Size Extra Small weighs 2.2 pounds and can be worn on the left or right foot. USER GUIDE included in each boot for proper application. Please follow the steps provided for ideal fit and comfort PROMOTES NATURAL WALKING with rocker sole and shock-absorbing insole promote more natural walking during use STURDY plastic molded uprights with steel reinforcement provides increased durability CAM WALKER BOOT can be used for acute ankle sprains, soft tissue injuries, stable lower leg, foot and ankle fractures and post-operative use. The United Ortho air cam walking boot provides maximum stability and support following injury or post-operative procedures.