HR Mainspring No. 396 for Bulova 4AC, 6E, 6AO, 6TA, 6TAA, 7HI, 7M - Steel

HR Mainspring No. 396 for Bulova caliber 4AC, 6E, 6AO, 6TA, 6TAA, 7HI, 7M movements, plus perhaps others, steel, new in envelope. See images for precise mainspring specifications. Now to editorialize a bit...I know this is the correct mainspring for the 6AO and is suitable for the 6TA & 6TAA but the others I cannot confirm, which is unusual. I like to check them to make sure it will fit before you go to use it so I wanted to point this out.  I specialize is 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.