Amazon.com: CKPSMS Brand- Extra/Spare Sewing Machine Spool pin (The Inner Diameter of The Opening is 3mm) Works for Sewing Machine Bobbin Winder Spindle
Spool Pin for the Singer 15, 201 Sewing Machine – The Singer Featherweight Shop
Singer Featherweight 221 222K Spool Pin Spring – The Singer Featherweight Shop