HR Nivastar Mainspring G621 for AS 1171, 1173, Kurth 257, 258 - Alloy

HR Nivastar Mainspring G621 for AS 1171, 1173, Kurth 257, 258 caliber movement plus perhaps similar ébauche watches, white alloy. See images for precise characteristics. I likely have several of these so the one you get may differ very 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 a pretty good job of representing the item.