HR Quick Fit Mainspring K304 for Gruen caliber 235, 430, 431, 435, 440 - Alloy

HR Quick Fit Mainspring K304 for Gruen 235, 430, 431, 435, 440 caliber movements plus perhaps many more similar ébauche watches, white alloy. See image 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 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.