Cathy; Your explanation of the ziper feet being the only ones used plus the standard foot makes a lot of sense. I just wish those boxes would breed some zipper feet instead of all the rufflers, hemmers and miscellaneous bits and pieces that I do have currently. One other thing I noticed is that most of my boxes still have the seam guide still in them which I think odd simply because it's such a neat gadget one would think it got used frequently if not all the time unless their eyeballs calibrated better then than mine do today.