The Vintage Singer Buttonholer Attachment 160506 is a sewing machine accessory designed specifically for Singer machines. This attachment allows for creating buttonholes with precision and ease. The green case manual indicates that this product is a vintage item, adding a unique and collectible aspect to any sewing enthusiast's collection. Compatible with Singer machines, this buttonholer attachment is a valuable addition to any sewing workshop for those looking to add a touch of nostalgia to their crafting projects.