Elgin 21/0s Mainspring No. 5327 / 6004 (EXACT) - Alloy

Elgin EXACT Mainspring for 21/0s Movements, Factory No 5327 / 6004, alloy, 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 pretty good job of representing the item.