HR Mainspring A553 for 0s Rockford #1077 - Steel

HR Mainspring A553 for Rockford 0s Movements, Factory No. 1077, steel, new in dirty 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 suitable job of representing the item.