Swartchild Black Shield Jr Mainspring for Font 60, AS 1173, Bulova 7AL, 7AF - Steel

Swartchild Black Shield Jr Mainspring for Font 60, AS 1173, Bulova 7AL, 7AF, Kurth 257, 270, Buren 355 caliber movements, steel, new in envelope. These springs are packed in a smaller envelope for smaller caliber watches, hence the "Jr" designation. I likely have several of these so the exact packaging may be different. I specialize in hard to find watch & clock parts and all parts are unconditionally guaranteed. Images do a pretty good job of representing the item