Comsco Mainspring #10420 for Waltham 8¾ ligne Model 870 No. 2242 - Steel

Comsco Mainspring #10420 for Waltham 8¾ ligne Model 870 movements, Factory No. 2242, steel, new in envelope. See images for precise mainspring specifications. I specialize is hard to find watch parts and all watch parts are unconditionally guaranteed. Images do a pretty good job of representing the item.