Marco Mainspring #611 for Howard 16s No. 329 - Steel

Marco Mainspring #611 for Howard 16s 1906 & 1907 model movements, Factory No. 329, steel, new in possibly frail envelope. See images for precise mainspring 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.