Waltham 18s Mainspring Factory No. 2202 from S. LaRose - Alloy

S. LaRose packaged (likely Swiss made) Mainspring for 18s Waltham model 1857 movements, Factory No. 2202, alloy, new in package. See images for precise mainspring specifications, although the width is closer to 19½. 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.