Birkenstock Boston gunmetal nubuck leather is a robust mule with a rustic look. The leather top layer is easy to maintain because of the smooth surface. The anatomically shaped cork latex footbed features a deep heelbed and toe grip which gives extra comfort to the foot. Because latex is incorporated into the footbed it seems like you are walking on soft cushions. This model is due to the strap across the instep easy to adjust to the foot. The mule can be worn both indoors and outdoors. Birkenstock Boston gunmetal is available in the 'normal' width.