Product review (3 stars): It would be best to have the items labeled "old style" and "new ...
This is a "new style" knob that is slightly too loose for older viking ranges.  While they look the same, the hole in the knob is just slightly too large, although the knob works.  I fixed this by placing two layers of scotch tape over the metal on the range, and then the knob fit perfectly.  It would be best to have the items labeled "old style" and "new style" and to let us DIY'ers know the difference before we order......