Green Mountain Mainspring for Hampden 3/0s No. 9696 - Steel

Green Mountain Mainspring made by Waltham for Hampden 3/0s movements Such as the Molly Stark, the Diadem & Model 400, Factory No. 9696, steel, new in envelope. See image for further details. Why Waltham chose to call these Green Mountain instead of just the typical generic "Unit Resilient Main Spring" they manufactured for use on watches other than their own may forever be a mystery. I have quite a few of these and they don't all look exactly the same 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 marginally adequate job of representing the item