{"product_id":"nivaflex-unbreakable-mainspring-n4311-for-eterna-600-gruen-153-font-344-8344-many-more-alloy","title":"Nivaflex Unbreakable Mainspring N4311 for Eterna 600, Gruen 153, Font 344, 8344 +many more - Alloy","description":"\u003cp\u003e\u003cstrong\u003eNivaflex\u003c\/strong\u003e Unbreakable mainspring N 4311 for Eterna 600, Font 344, 8344, Gruen 153, Langendorf 12, 722, MTS 321, 322, 327, 348, 356 and even more calibers plus perhaps other similar \u003cspan class=\"st\"\u003eébauche\u003c\/span\u003e movements as well, alloy, new in envelope. See images for all supported calibers and 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":"Nivaflex","offers":[{"title":"Default Title","offer_id":48600251433268,"sku":"PMS-NIVAN4311A-06","price":6.0,"currency_code":"USD","in_stock":false}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0849\/3341\/1124\/files\/2025-05-2713.18.57.jpg?v=1748377228","url":"https:\/\/www.vintagetimeparts.com\/products\/nivaflex-unbreakable-mainspring-n4311-for-eterna-600-gruen-153-font-344-8344-many-more-alloy","provider":"Vintage Time Parts","version":"1.0","type":"link"}