Samson Mainspring No. 10185 for Valjoux caliber 54, 55, 61 Chronograph - Steel

Samson No. 10185 steel mainspring for Valjoux caliber 54, 55, 61 & Breitling caliber 109 chronographs and perhaps others, 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 so I usually have whatever you might need and all watch parts are unconditionally guaranteed. Images do an adequate job of representing the item.