Singer Sewing Machine Slotted Clamping Thumb Screw for Buttonholer Blind Stitch Zigzag Attachment 140530

Vintage Singer sewing machine attachment thumb screw, also know as the slotted clamping screw - This style screw originally accompanied the buttonholer, blind stitch & some zigzagger attachments, but of course you can use it for whatever you like! Very nice vintage condition, rust free. Genuine Simanco part #140530