Ergoplay Tappert/Tröster Suction Cups

I bought it as a guitar footrest. Spare part. Unfortunately, it is not the same as the others. Maybe I should have ordered more so that they stick equally. It works, even better quality than the one I bought with the footrest, but unfortunately the size is not exact for the metal part of the footrest. It serves its purpose, but I will probably have to replace the remaining three in the future.