Elgin Factory DuraPower Mainspring for 10/0, 16/0 and 18/0s No. 6099 - Alloy

Elgin Factory DuraPower Mainspring for 10/0s, 16/0s & 18/0s movements, Factory No. 6099, alloy, new in envelope. See images for further specifications. This mainspring came in several strengths and those that I can provide are shown in the drop-down list. I specialize in hard to find watch parts and all watch parts are guaranteed. Images do a pretty good job of representing the item