Amazon.com: SINGER | Spare Bobbin Case for SINGER Sewing Machines, Tension Screw to Sew Thicker Threads, Fits Class 15 Front-Loading Bobbin Systems - Sewing Made Easy
Amazon.com: ckpsms Brand - Bobbin Case #125291 Fit for Singer 15-88, 15-90, 15-91 OR 15-125 Sewing Machine (4PCS)
Amazon.com: SINGER 06543 Class 15J Bobbins, Transparent, 12-Count