Vigor TONGUE End Clock Mainspring for Muller caliber 26 - 21 x 3½ x 25" Long - T 300.4

Vigor Clock Mainspring, TONGUE End – Dennison 21 x 3½ x 25" in Length, P/N T 300.4, GR Ref 30-20 C 62, 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 in hard to find watch & clock parts and all parts are unconditionally guaranteed. Images do a pretty good job of representing the item.