HR Mainspring for Benrus caliber BU & Tavannes caliber 384-6 - Steel

HR No. 491 steel mainspring for Tavannes caliber 384-6 and Benrus caliber BU bracelet movements and perhaps others, new in envelope. See images for precise 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.