Swartchild OPEN LOOP Clock Mainspring - 7/64" x .009" x 18½" Long

Swartchild & Co. Clock Mainspring, OPEN LOOP End – 7/64″ Width, .009″ Strength/Thickness, 18½″ Length, steel, new in package. I have yet to find a clock that uses this mainspring but it was undoubtedly made for a small clock.  See images for precise mainspring specifications. 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.