Samson Mainspring No. 9051 for Venus 170 Chronograph movements - Steel

Samson steel mainspring No. 9051 for Venus caliber 170 chronograph movements as well as a bunch of A.S. calibers, new in frail 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.