Alloy Mainspring for Certina caliber 204, MST caliber 281

Nivastar Swiss Mainspring for Certina caliber 204 & MST caliber 281 movements plus perhaps similar ébauche watches, GR Ref. 2576, white alloy, new in tiny 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 a pretty good job of representing the item.