I have a few sets and really love how they work out. I'm pretty sure you only purchase one size, I've bought the mega size. Sometimes I will enlarge it a bit on my machine, but find that you can only go a little bit or the stitch length gets too long, as it does not redigitize it, only makes everything larger. Not like the LA that adjusts so the stitch length stays the same even if you change a 5" design into a 15" design.