{"product_id":"swartchild-black-shield-mainspring-b4391-for-16s-trenton-no-1365-steel","title":"Swartchild Black Shield Mainspring #B4391 for 16s Trenton No. 344 - Steel","description":"\u003cp\u003e\u003cstrong\u003eSwartchild \u003c\/strong\u003e\u003cem\u003eBlack Shield\u003c\/em\u003e Mainspring #B4391 for 16s \u003cstrong\u003eTrenton\u003c\/strong\u003e Pocket Watches, Factory No. 344, steel, new in frail envelope. Could also very well fit in other watches as well. 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 and all watch parts are unconditionally guaranteed. Images do a pretty good job of representing the item.\u003c\/p\u003e","brand":"Swartchild","offers":[{"title":"Default Title","offer_id":48468349944116,"sku":"PMA-SWB4391S-02","price":7.5,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0849\/3341\/1124\/files\/2025-02-12_16.38.57.jpg?v=1739407428","url":"https:\/\/www.vintagetimeparts.com\/products\/swartchild-black-shield-mainspring-b4391-for-16s-trenton-no-1365-steel","provider":"Vintage Time Parts","version":"1.0","type":"link"}