CR Mainspring #410 for 12s Illinois Factory No 47345 - Steel

Charles Robert Mainspring #410 for 12s Illinois, Factory No. 47345 (super old number was 1236), T brace, steel, new in frail cellophane envelope. See images for precise mainspring specifications. This can be a tough mainspring to find. I specialize in hard to find watch parts and all watch parts are unconditionally guaranteed. Images do a barely adequate job of representing the item.