The product I was able to install without problems. Moreover, it is relatively safe because the 5-square-closure is a failed method. Thus, it is impossible to just quickly dismount the tires or the saddle for Gelgenheitsdiebe.
Conclusion: A cheap method to protect his tires and the saddle. In addition, the set goes on the most common bike models and is easy to assemble / disassemble (advance law you lose the key not)