Good quality plastics and beautiful design. In order for them not to come off, they need to be installed correctly. There are simple instructions on the back that you need to follow. First, wash the rim well, especially around it, and then place the metal clamp on the rim and secure it. Then, test if you can easily remove it or if you can twist it on the rim (which should not happen if the installation is correct). If it twists or comes off easily with a simple pull, the metal clamp needs to be removed from the rim and bent or adjusted, and then reinstall it until it is difficult to remove and requires a strong pull.

Very nice indeed, but... I have had them for about 3 months and both of them have come off (I had them tied and with cable ties). The worst part is that they are only sold in packs of four