The Birkenstock Boston clog has an adjustable strap ensuring an individual fit. The highest quality leather is used – between 2.8 and 3mm thick. The leather footbed makes them comfortable to wear and creates a pleasant environment for the entire foot. These clogs are suitable for a range of occasions whether indoors or out. Narrow Fit * Natural oiled leathers appear stressed and rustic looking. They have a visible grain and naturally occurring colour irregularities that are deliberately not removed in production in order that the natural matt surface of the leather is preserved. Applying a leather conditioner will minimise this appearance or rubbing scratches gently with your hand. The oily finish of all natural leather products results in Colour and Shade Variations making each and every pair unique.