Swartchild Black Shield Clock Mainspring 2.5 x .21 mm x 17¾" Ref 25-21 B 45

Swartchild & Co Black Shield Clock Mainspring, OPEN LOOP End, for Schuler 11, GR Ref. 25 - 21 B 45, steel, made in France. See images for precise mainspring specifications. I specialize is hard to find watch & clock parts and all parts are unconditionally guaranteed. Images do a pretty good job of representing the item