HR Mainspring No. 728 for Font 2124 thru 2144 caliber movements

HR No. 728 steel mainspring for Font 2124 thru 2144 caliber movements. See images for precise calibers supported and mainspring specifications. 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.