Upper/lining/sole -1 Pc. Molded EVA, Ultra lightweight, Resin Buckle, Washable, Waterproof, Shock Absorbing Soft Thong. Perfect for Beach, Backyard Pool BIRKENSTOCKS Description of features THE LEGENDARY DESIGN OF BIRKENSTOCKS ORIGINAL FOOTBED CONSTRUCTION- was designed with the smallest of details to make you feel like you were standing in sand, while making your feet as comfortable as possible for hours on end. DEEP HEEL CUP-holds heel bone firmly in natural position, HEEL MOLD-Activate Calf Muscles, stabilizes back of foot, Improves Gait coordination INTERIOR EXTERIOR LONGITUDINAL ARCH SUPPORTS-they run along the sides of footbed providing support for the tarsal bones inside out. Giving the stability the foot needs when you step TRANSVERSE ARCH SUPPORT-Runs through the middle of the footbed stabilizing the Metatarsal Bone. The Transverse Arch Support helps ensure the foot has a naturally straight solid stance TOE GRIP-the raised front indentations toe grips keep the toes loose spread in natural position support the natural rolling motion of toes RAISED FOOTBED EDGE-is especially high up front which protects the toes during rolling motion of a foot