Swartchild Mainspring 4402A or 16s Howard Factory No. 2323 (328) - Steel

Swartchild Mainspring 4402A for 16s Howard, Factory No. 2323, steel, new in envelope. See images for further details. The Old Factory No is 2323, which is relatively close to a 328 which measures between 2.75 and 2.80mm, depending on your reference guide - I've provided the one for this mainspring (see last image). I specialize in hard to find watch parts and all watch parts are unconditionally guaranteed. Images do an adequate but perhaps somewhat incomplete job of representing the item.