HR Quick Fit Mainspring K510 for Excelsior Park 3364R timer - Alloy

HR Quick Fit Mainspring K510 for Bulova 17AB pocket watches and the Excelsior Park 3364R timer, white alloy. Not sure whether this also fits the 3364 Park timer, but I would presume not. See image for precise characteristics and further helpful information. 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 a pretty good job of representing the item.