HR Quick Fit Mainspring No. K429B for Font 61, 120, 123, Benrus AB & AS 1240 - Alloy

HR Quick Fit Mainspring No. K429B for Font 61, 120, 123, Benrus AB & AS 1240 caliber movements, alloy, new in envelope. See images for all calibers supported 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 satisfactory job of representing the item.