The listing, Niken Pleater Sewing Machine Accessory Part Sew Pleats has ended.
Used this pleater attachment with my Singer many years ago.
I don't have any instructions for this item.
There are 4 option settings for the pleats, labeled *, 12, 6, & 1. ( Second photo )
There is also an adjustable screw to lengthen or shorten the pleat I assume. It has these measured numbers: 1, 4, 6, 8. ( Third photo )
Thank you.