Narrow width Durable one-piece EVA construction Adjustable buckle straps Water-friendly Anatomically-shaped footbed for support Lightweight outsole delivers premium flexibility and traction Birkenstocks best-selling shoe, turned water-friendly. The Birkenstock Women's Boston EVA are made from a durable one-piece EVA construction that allows you to wear them in and out of the pool without restriction. Designed with an adjustable buckle strap and a contoured foot-bed for support, this lightweight shoe was made for vacations, office days, and everything else in between. Product Code: 1029583