Boston Wool (Narrow)Birkenstock Boston is a classic that can be worn all year round. This version comes with a shaft in soft, high quality woolen felt. Slip on style One strap with an individually adjustable metal pin buckle Anatomically shaped footbed Suede lined soft footbed Narrow width Materials Upper: wool felt Outsole: EVA Made in Germany Size Guide Women's style listed in European sizing. Fits true to size. We recommend taking your normal size. For additional size