Birkenstock's first slipper model Madrid, which is unique with its simplicity and functionality, is also known as fitness slipper. ; While it provides a solid and upright posture thanks to its deep heel bed, the adjustable strap on the front supports the work of your back leg muscles by gripping your toes. ; Launched half a century ago as a gymnastics sandal, this simple single strap model has become a fashionable favorite today. ; Thanks to Madrid, every step you take will now be softer and healthier. ; BIRKENSTOCK Madrid slipper is a favorite piece of the fashion world with its minimalist design.;