The Madrid sandal is the most well-known Birkenstock in the range. This model has been around for decades without any changes to the foot bed or the adjustable strap. The Birkenstock Madrid is one of the most elegant models in the range, with the familiar, comfortable foot bed. Every year, the Madrid collection expands with the most trendy colours and prints. The Birkenstock Spectral Silver in leather is a must-have for fashionistas who want to try something special. The silver colour can be combined with many outfits. By default, these slippers come with a narrow foot bed. Even if you have a wide model in your flip flops, you will probably still need a Madrid flip flop with a narrow foot bed. Birkenstocks are very large. You may need a size smaller than in other shoes.