...wheels. Every bike has a pair of them. This particular one was standing on Zimmerstrasse in Berlin. There were loads of this bikes around the city and I must say that they seem very though and practical - durable enough to ride day after day around whole city without a problem and even if something breaks - super easy to repair.
In addition to this they have this bright orange-red color on wheels and basket, which makes them stand out on the street - one of the reasons I captured this photo ;)