Swartchild Black Shield Mainspring for 18s Waltham No. 2203 - Alloy

Swartchild Black Shield Mainspring for 18s Waltham Movements, Factory No. 2203, alloy, new in envelope. See image for further details. Envelope suggests it is a T-brace end but it is a T end. I specialize is hard to find watch parts so I usually have whatever you might need and all watch parts are unconditionally guaranteed. Images do an adequate job of representing the item.