HR Nivastar Mainspring G304 for Gruen caliber 235, 430, 431, 435, 440 - Alloy

HR Nivastar Mainspring G304 for Gruen caliber 235, 430, 431, 435, 440, white alloy, 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 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.