{"product_id":"marco-mainspring-3137-for-omega-r13-5-240-fleurier-50-derby-50-steel","title":"Marco Mainspring #3137 for Omega R13.5 (240), Fleurier 50, Derby 50 - Steel","description":"\u003cp\u003e\u003cspan style=\"font-size: 14px;\"\u003e\u003cstrong\u003eMarco \u003c\/strong\u003eMainspring No. 3137 for Omega R13.5 (also known as 240), Fleurier 50 and Derby 50 caliber movements, and perhaps other similar ébauche watches, steel, new in envelope. See images for precise mainspring specifications. Note please is says Omega R 13.15 which is a typo. I likely have several of these so the one you get may differ slightly from the images. I specialize is 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. \u003cbr\u003e\u003c\/span\u003e\u003c\/p\u003e","brand":"C \u0026 E Marshall","offers":[{"title":"Default Title","offer_id":49017224298804,"sku":"PMS-CEM3137S-01","price":6.0,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0849\/3341\/1124\/files\/2026-01-2918.53.06.jpg?v=1769741781","url":"https:\/\/www.vintagetimeparts.com\/products\/marco-mainspring-3137-for-omega-r13-5-240-fleurier-50-derby-50-steel","provider":"Vintage Time Parts","version":"1.0","type":"link"}