{"product_id":"marco-marshalloy-mainspring-2717m-for-gruen-335-430-431-435-440-alloy","title":"Marco Marshalloy Mainspring 2717M for Gruen 335, 430, 431, 436 \u0026 440 - Alloy","description":"\u003cp\u003e\u003cstrong\u003eMarco \u003c\/strong\u003e\u003cem\u003eMarshalloy\u003c\/em\u003e\u003cstrong\u003e \u003c\/strong\u003eMainspring No. 2717M for \u003cstrong\u003eGruen\u003c\/strong\u003e caliber 335, 430, 431, 436 \u0026amp; 440 movements plus perhaps other similar \u003cspan class=\"st\"\u003eébauche\u003c\/span\u003e movements as well, alloy, new in envelope. See images for precise mainspring specifications. 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 pretty good job of representing the item.\u003c\/p\u003e","brand":"C \u0026 E Marshall","offers":[{"title":"Default Title","offer_id":48901858689332,"sku":"PMS-CEM2717MA-09","price":12.0,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0849\/3341\/1124\/files\/2025-09-2114.01.23.jpg?v=1758488867","url":"https:\/\/www.vintagetimeparts.com\/products\/marco-marshalloy-mainspring-2717m-for-gruen-335-430-431-435-440-alloy","provider":"Vintage Time Parts","version":"1.0","type":"link"}