Sandsteel Sandalloy Mainspring S2203 for ETA 705, AV 16, Buren 300, 301, Pierce 53 - Alloy

Sandsteel Sandalloy Mainspring S2203 for ETA 705, AV 16, Borel INCA STAR, Buren 300, 301, Chezard 50 53, Kurth 83, 87, Pierce 53, Urofa 54 caliber movements, plus perhaps similar ébauche watches, 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 so I usually have whatever you might need and all watch parts are unconditionally guaranteed. Images do a barely adequate job of representing the item.