Through the narrow arm of the holder can also be mounted in tight spaces. For me it is about 14 cm between the 50 cm deep basin cabinet and the 32 cm deep bathroom cabinet. This is enough, however, and I'll handle it well.
The assembly is somewhat tricky, since two 6 mm holes have to be drilled at a small distance, with which a mounting plate is fixed to the wall. At this mounting plate of the towel rail is fastened with a very small Allen grub screw. Here you have the hex wrench very close to the wall and that takes some patience - but ultimately keeps.