KBK Mainspring #3020 for South Bend 16s Factory No. 27528 - Steel

Kilb - Beck - Kuesel Inc (KBK) Genuine Factory Mainspring #3020 for South Bend 16s movements, Factory No. 27528, new in envelope. See images for precise mainspring specifications. As the envelope says these are Genuine Factory Mainsprings which means the came from the factory but does NOT mean South Bend made them as all South Bend Mainsprings were made by Sandsteel. I likely have several of these so the one you get may differ slightly from the images. I specialize in hard to find watch parts and all watch parts are unconditionally guaranteed. Images do a pretty good job of representing the item.