Waltham Mainspring for Model 660 (FF 60) No. 6-681 - Steel

Marco mainspring for Waltham 6 ¾ x 8 ligne Model 660 movements, #6-681, steel, new in envelope. The 6 ¾ x 8 ligne movements are FF 60 ébauche based so this mainspring will fit movements other than just the specified Waltham. See image for further details. I specialize in hard to find watch parts and all watch parts are unconditionally guaranteed. Images do a pretty good job of representing the item