CR Mainspring #705 for Seth Thomas Mainspring for 12s Factory No. 2521 - Steel

CR Mainspring #705 for Seth Thomas 12s movements, Factory No. 2521, steel, new in envelope. See image for precise mainspring specifications. While the plastic wrappers are often old and fragile the mainsprings are new and unused. I specialize in hard to find watch parts and all watch parts are unconditionally guaranteed. Images do an adequate job of representing the item.