Waltham Factory Mainspring for 10s 1861 Model 2213 - Steel

Waltham Factory Mainspring for 10s 2nd Series Model 1861 Keywind Movements, Factory No. 2213, hole end, steel, new in envelope. See image for further details. I likely DO NOT HAVE several of these because this is the first one I've had since the 1990's. I specialize in hard to find watch parts so I usually have whatever you might need and all watch parts are unconditionally guaranteed. Images do a pretty good job of representing the item.