Newall SUPER Security Mainspring #558 for Waltham Jewel Series 6/0s No. 2235 - steel

Newall SUPER Security Mainspring #558 for Waltham Jewel Series 6/0s, factory No. 2235, steel, new in likely distressed envelope. See image for further details and precise specifications. I likely have several of these so the one you get may differ slightly from the images. I specialize in hard to find watch parts and all watch parts are unconditionally guaranteed. Images do a pretty good job of representing the item.