N. B. Mainspring for Buren 30, 70, Derby 27, Gruen 746, Font 45, Unitas 411 - Alloy

N.B. Alloy mainspring several Swiss wrist watch movements, including, but not limited to the following;

Mainspring is new in envelope. See images for precise mainspring specifications.  The number shown is the Newall P/N for this 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.