Sandsteel Mainspring for Howard 16s Factory No. 328 - Steel

Sandsteel Mainspring for Howard 16s Model 1906 & 1907 movements, Factory No. 328, steel, new in likely frail envelope. See images for further details. I likely have several of these so the one you get may differ slightly 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.