HR Mainspring No. 542 for Benrus AG, BF, BG, AS 340, ETA 1051 movements - Steel

HR Mainspring No. 542 for Benrus AG, BF, BG, Tavannes 010, AS 340 and ETA 1051 caliber movements, steel, new in envelope. See images for all supported calibers 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 a pretty good job of representing the item.