Thanks for reply! I'm not sure about english-terms, but it is a freewheel then. But is it Uniglide, or does that UG/VG mean something else? How I choose the right freewheel remover, or is it somehow "universal"? I was hoping that if it's Uniglide, I could flip the sprockets. But if I have to replace the whole cassette, is it possible to find similar 5-speed cassette?