I use the Singer buttonholer on my featherweight and on my Janome 6500 all the time as I don't like the automatic built in buttonholer on my Janome. The buttonholer for a featherweight will fit any short shank machine including newer machines. I am puzzled however Tommilou as to how the buttonholer you purchased will fit either short shank or slant machines as the slant shank machines wouldn't have the screw hole needed to attach the buttonholer in the same place and the buttonholer would sit too high. Slant shank buttonholers have their attachment post in a different spot. Everything else about them is the same.