Tru-Temper Mainspring for Gruen 405, 406, 410, 411, 420 & 425 caliber movements - Steel

Tru-Temper Mainspring for Gruen caliber 405, 406, 410, 411, 420, 425 caliber movements, and perhaps several others, steel, new in envelope. See images for precise mainspring specifications. I specialize in hard to find watch parts so I usually have whatever you might need and all watch parts are unconditionally guaranteed. Images do an adequate job of representing the item.