Today I wanted it in a Veloflex Ringbuch Comfort / 4151080 DIN A5, I also bought some time ago from Amazon, but not yet used to use, but they did not fit. This ring binder has a 4-D-ring mechanism. When you insert the punched pockets in the middle and above the lower hole is not and vice versa fits when it fits the bottom and in the middle, they do not match up. You have to literally "getting involved". But then one can no longer turn over reasonable the individual punched pockets, because they too are on voltage either up or down.
At first I thought that it indeed might be the ring binder and sought punched DIN-A-5 paper. But lo and behold, that fit into any problems. If one puts a perforated DIN-A-5 sheet on the Sheet protectors, it is found that the outer holes of the cases can not be brought into alignment. Either it fits up or down. Missing about 3mm.
I have then made do with the fact that I have extended the upper hole with a punch to the top. If you try this with a punch, it is a matter of luck, in what direction widens the hole - that's at least my experience.
Because of the inaccuracy of fit when used with a 4-ring mechanism, I can not forgive only three stars, otherwise it would have been five stars considering the price.
