Originally Posted by thepolyparrot

I'm not sure which machines these would go with, but the designs match some of the designs that came out with the 700 series of Touch & Sew machines - the first ones that could include reverse stitches in the sequence.

The ones made for the T&S machines were white - they look like the black "top hat" cams that fit 400, 500, 600 & 700 series machines, but they have an additional guide track on the bottom of the disk to direct forward and reverse.