{"product_id":"pm-mainspring-no-384-for-gruen-caliber-580-581-582-587-onyx-steel","title":"PM Mainspring No. 384 for Gruen caliber 580, 581, 582, 587 - ONYX Steel","description":"\u003cp\u003e\u003cstrong\u003ePM \u003c\/strong\u003eONYX steel Mainspring No. 384 for \u003cstrong\u003eGruen\u003c\/strong\u003e caliber 580, 581, 582, 587 movements and quite likely others, new in envelope. See images for precise mainspring specifications. 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 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":"PM","offers":[{"title":"Default Title","offer_id":49127847821620,"sku":"PMS-PMMS384S-05","price":4.0,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0849\/3341\/1124\/files\/2026-05-1416.27.30.jpg?v=1778801483","url":"https:\/\/www.vintagetimeparts.com\/products\/pm-mainspring-no-384-for-gruen-caliber-580-581-582-587-onyx-steel","provider":"Vintage Time Parts","version":"1.0","type":"link"}