{"product_id":"usr-mainspring-for-hamilton-12s-1228-steel","title":"USR Mainspring for Hamilton 12s No. 1228 - Steel","description":"\u003cp\u003e\u003cstrong\u003eUSR \u003c\/strong\u003esteel mainspring for \u003cstrong\u003eHamilton\u003c\/strong\u003e\u003cstrong\u003e \u003c\/strong\u003e12s movements, Factory No. 1228 (and likely 3028 as well), new in envelope. See images for further details. 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 a pretty good job of representing the item.\u003c\/p\u003e","brand":"USR","offers":[{"title":"Default Title","offer_id":47451922006324,"sku":"PMA-USR1228S-10","price":3.5,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0849\/3341\/1124\/files\/2025-10-04_19.53.14.jpg?v=1759632854","url":"https:\/\/www.vintagetimeparts.com\/products\/usr-mainspring-for-hamilton-12s-1228-steel","provider":"Vintage Time Parts","version":"1.0","type":"link"}