BOREL Mainspring SA354 for Howard 12s No. 552 - Alloy

BOREL Mainspring SA354 for Howard 12s, Factory No. 552, alloy, new in envelope. See images for precise mainspring specifications. 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 an adequate job of representing the item.