HR Mainspring No. 431 for MST 325, Peseux 140 - Steel

HR Mainspring No. 431 for MST (Meyer & Studeli) caliber 340 and Peseux caliber 140 movements plus perhaps other ones as well, steel, new in envelope. See images for further data and 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 so I usually have whatever you might need and all watch parts are unconditionally guaranteed. Images do an adequate job of representing the item.