BESTFIT Mainspring 412H for Aurore 17, Omega R17.3, Unitas 540 - Alloy

BESTFIT Mainspring 412H for Aurore 17, Omega R17.3, Unitas 450, AS 945, 1194 plus perhaps similar ébauche watches, white alloy, new in possibly frail envelope. See images for precise mainspring specifications. I likely have several of these and the envelopes look slightly different but they are all the same mainspring. 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 a pretty good job of representing the item.