Not more than a deterrent

The castle listed here allows a simple lock my bicycle between tire and frame. A link between bike racks, fences or lanterns is possible.
It is very convenient to install, since it is not wound into a small coil, which I personally like good. The resulting disadvantage is of course the lack of space savings.

Of course, the lock does not provide very high security and can be easily with a bolt cutter cutting. However, this already requires a certain amount of criminal energy. A first deterrent effect should be achieved through the castle, however.

For my needs, the bicycle lock is adequate and the price is absolutely nothing to complain about.