Elgin Factory Mainspring for 26/0s No. 5131 (300A) - Steel

Elgin Factory Mainspring for 26/0s movements, # 5131 (factory 300A), steel, new in envelope. Actual mainspring sleeve may differ slightly from the image and some of the envelopes are in better shape than others. See image for further specifications. Elgin mainsprings are typically coated in very old grease and must be cleaned before use. I specialize is hard to find watch parts and all watch parts are unconditionally guaranteed. Images do a pretty good job of representing the item