BESTFIT Mainspring 312H for Bulova caliber 6AP, 6B, 6BB, 6BBI & ETA 750, 751 - Alloy

BESTFIT Mainspring 312H for Bulova caliber 6AP, 6B, 6BB, 6BBI, AS 427 & ETA 750, 751 plus perhaps others, alloy, new in envelope. See images for 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.