I really like my side-winder (think that is what it is called). Mine is pink which accepts the Viking Rose machine's bobbins. As far as I know the Viking will not take the pre-wound. I normally wind 3-4 in advance (depends on what I am sewing)and if I don't have enough so easy to wind another bobbin or two on the fly without having to unthread and rethread my machine. Saves wear and tear on your machine and is small enough to take with you to quilt classes, retreats, camps, etc.