Old style bobbins that do not have space for the magnet and will not fit magnetized wheels.
New style bobbins that do have space for the magnet will fit non-magnetized wheels. If you want to replace your old bobbins with new bobbins, we recommend selling your old bobbins on our Facebook Group or Ravelry page to other SpinOlution spinners who have wheels that will work with those bobbins.