HR Mainspring SA206 for 16s Hamilton Factory No. 317 / 718042 - Alloy

HR Mainspring SA 206 for Hamilton 16s 17-21 Jewel Movements, Factory No. 317 / 718042, alloy, new in dirty envelope. See image for precise characteristics. I likely ave several of these so the one you get may differ slightly from the images. I specialize is hard to find watch parts and all watch parts are unconditionally guaranteed. Images do an adequate job of representing the item.