Vigor TONGUE End Clock Mainspring - 21 x 2 x 21½" Long - T 300.6

Vigor Clock Mainspring, TONGUE End – Dennison 21 x 2 x 21½" in Length, P/N T 300.6, steel, new in envelope. See images for precise mainspring specifications. I likely have several of these so the one you get may differ slightly from the images.  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.