I have a 15-91, love the machine but only do straight stitch sewing. It belonged to my mom, it was a wedding present from her parents in 1950. It has an embroidery attachment - I have to admit I have never used it. So don't know how it works. When I used the button hole attachment for the first time in 50 years, I almost went into hysterics laughing. I had forgotten how it throws the fabric back and forth. My mom was a great seamstress, so she used them.