BSTNSHER Birkenstock Boston Shearling The signature slip-on clog from BIRKENSTOCK - the Boston. A casual-wear staple that is perfect all year round with a simple, adjustable design and contoured cork footbed that forms to the shape of your foot. Here, the classic model comes in a particularly cozy version with soft shearling lining. The perfect shoe for cozy winter evenings! The upper is made from soft suede.