Swartchild Black Shield Mainspring for 6/0s Benrus 7j - Steel

Swartchild Black Shield Mainspring #21236 for 6/0s Benrus 7j wrist watch, steel, new in envelope. See images for precise mainspring specifications. I specialize in hard to find watch parts and all watch parts are unconditionally guaranteed. Images do a pretty good job of representing the item.