Now that I have a nice European handmade violin, I put these octave strings on my first, Chinese factory-made violin. It gives the violin a range in between the viola and the cello. The strings are markedly slower in response than regular violin strings, but you can still do cool things with them. Just don't use them to swap back and forth with regular strings on the same instrument, as the octave strings will alter the grooves on the bridge, which will make it probably unsuitable for regular strings afterwards.