Swartchild Black Shield Mainspring #4351 for Hampden 3/0s No. 9696 - Steel

Swartchild Black Shield Mainspring #4351 for Hampden 3/0s movements Such as the Molly Stark, the Diadem & Model 400, Factory No. 9696, steel, new in envelope. See images for precise mainspring specifications. I likely have several of these 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