{"product_id":"seiko-selection-open-heart-hfb004j-mens-watch","title":"Seiko Selection Open Heart  HFB004J Men's Watch","description":"\u003cp data-path-to-node=\"6\" id=\"p-rc_4d186887a5d0b1a9-384\"\u003e\u003cspan class=\"citation-1496\"\u003eThe \u003c\/span\u003e\u003cspan class=\"citation-1496\"\u003eSeiko Selection HFB004J\u003c\/span\u003e\u003cspan class=\"citation-1496\"\u003e (also designated across Japanese domestic catalogs as the \u003c\/span\u003e\u003cspan class=\"citation-1496\"\u003eHFB004\u003c\/span\u003e\u003cspan class=\"citation-1496\"\u003e within the celebrated \u003c\/span\u003e\u003cspan class=\"citation-1496\"\u003eSeiko Selection S Series Mechanical Collection\u003c\/span\u003e\u003cspan class=\"citation-1496 citation-end-1496\"\u003e) is a distinguished, high-performance Japanese automatic mechanical open-heart dress-sports timepiece.\u003csup class=\"superscript\" data-turn-source-index=\"1\"\u003e\u003c!----\u003e\u003c\/sup\u003e\u003c\/span\u003e Serving as the premier two-tone offering in the newly revamped S Series lineup, this reference embodies the core philosophy of the Seiko Selection line: a harmonious blend of refined design, everyday durability, and accessible Japanese mechanical excellence. \u003cspan class=\"citation-1495\"\u003eAcross horological forums, collector communities, and Japanese watch circles, it has earned defining community nicknames—the \u003c\/span\u003e\u003cspan class=\"citation-1495\"\u003e\"Open Heart\"\u003c\/span\u003e\u003cspan class=\"citation-1495\"\u003e, \u003c\/span\u003e\u003cspan class=\"citation-1495\"\u003e\"Two-Tone Open Heart\"\u003c\/span\u003e\u003cspan class=\"citation-1495\"\u003e, \u003c\/span\u003e\u003cspan class=\"citation-1495\"\u003e\"S Series\"\u003c\/span\u003e\u003cspan class=\"citation-1495\"\u003e, \u003c\/span\u003e\u003cspan class=\"citation-1495\"\u003e\"Golden Open Heart\"\u003c\/span\u003e\u003cspan class=\"citation-1495\"\u003e, \u003c\/span\u003e\u003cspan class=\"citation-1495\"\u003e\"Silver And Gold Open Heart\"\u003c\/span\u003e\u003cspan class=\"citation-1495\"\u003e, or \u003c\/span\u003e\u003cspan class=\"citation-1495\"\u003e\"Semi-Skeleton Two-Tone\"\u003c\/span\u003e\u003cspan class=\"citation-1495 citation-end-1495\"\u003e—for its radiant sunburst silver-white dial, warm yellow gold-plated bezel and accents, signature open balance-wheel window, and balanced 40.0mm case architecture.\u003csup class=\"superscript\" data-turn-source-index=\"2\"\u003e\u003c!----\u003e\u003c\/sup\u003e\u003c\/span\u003e \u003cspan class=\"citation-1494 citation-end-1494\"\u003eIt unites a sculpted 316L solid stainless steel case accented with yellow gold-tone plating in a versatile 40.0mm diameter with a silver-white radial dial face, three-sided diamond-cut gold-tone hour batons, an open-heart mechanical aperture revealing the escapement, an in-house Japanese automatic mechanical caliber, durable Hardlex crystal glass, certified 100-meter water resistance, and an integrated two-tone solid stainless steel construction with an easy-adjust sizing system.\u003csup class=\"superscript\" data-turn-source-index=\"3\"\u003e\u003c!----\u003e\u003c\/sup\u003e\u003c\/span\u003e Perfectly calibrated for gentlemen seeking an aristocratic, versatile mechanical daily wearer that transitions effortlessly from boardroom presentations and corporate events to formal evening galas and smart-casual weekends. \u003c!----\u003e\u003c!----\u003e\u003c!----\u003e\u003c!----\u003e\u003c!----\u003e\u003c!----\u003e\u003c!----\u003e\u003c!----\u003e\u003c!----\u003e\u003cspan class=\"citation-1493 citation-end-1493\"\u003eThe defining visual centerpiece of this HFB004J reference is its multi-layered, sunburst silver-white dial face.\u003csup class=\"superscript\" data-turn-source-index=\"4\"\u003e\u003c!----\u003e\u003c\/sup\u003e\u003c\/span\u003e \u003cspan class=\"citation-1492 citation-end-1492\"\u003eFinished with an ultra-fine radial brushing technique, the light dial surface diffuses ambient lighting into warm, shimmering reflections that enhance visual depth.\u003csup class=\"superscript\" data-turn-source-index=\"5\"\u003e\u003c!----\u003e\u003c\/sup\u003e\u003c\/span\u003e \u003cspan class=\"citation-1491 citation-end-1491\"\u003ePositioned prominently at 9 o'clock is a signature open-heart circular aperture framed by a polished yellow gold-tone chapter ring, offering an unobstructed view into the oscillating balance wheel and escapement mechanism to showcase the living mechanical heartbeat of the movement.\u003csup class=\"superscript\" data-turn-source-index=\"6\"\u003e\u003c!----\u003e\u003c\/sup\u003e\u003c\/span\u003e \u003cspan class=\"citation-1490 citation-end-1490\"\u003eCircling the perimeter are three-dimensional, three-sided faceted applied baton hour markers finished in warm yellow gold with wide, rainbow-ground chamfered facets that reflect light with brilliance.\u003csup class=\"superscript\" data-turn-source-index=\"7\"\u003e\u003c!----\u003e\u003c\/sup\u003e\u003c\/span\u003e \u003cspan class=\"citation-1489 citation-end-1489\"\u003eFaceted gold-tone sword-style hour and minute hands glide over the face alongside a slender sweep seconds hand, delivering crisp legibility against the white dial plate.\u003csup class=\"superscript\" data-turn-source-index=\"8\"\u003e\u003c!----\u003e\u003c\/sup\u003e\u003c\/span\u003e The outer track features fine minute demarcations that ensure an uncluttered, balanced display. Framing the dial is a fixed, mirror-polished solid stainless steel bezel treated with rich yellow gold-color plating that seamlessly complements the two-tone bracelet design.  \u003c!----\u003e\u003c!----\u003e\u003c!----\u003e\u003c!----\u003e\u003c!----\u003e\u003c!----\u003e\u003c!----\u003e\u003c!----\u003e\u003c!----\u003e\u003cspan class=\"citation-1488\"\u003eBeneath its tailored exterior, the watch is driven by Seiko’s proven in-house \u003c\/span\u003e\u003cspan class=\"citation-1488\"\u003eCalibre 4R38\u003c\/span\u003e\u003cspan class=\"citation-1488 citation-end-1488\"\u003e Japanese automatic mechanical movement, engineered and manufactured at Seiko’s dedicated horological facilities in Japan.\u003csup class=\"superscript\" data-turn-source-index=\"9\"\u003e\u003c!----\u003e\u003c\/sup\u003e\u003c\/span\u003e \u003cspan class=\"citation-1487\"\u003eOperating at a steady frequency of 21,600 vibrations per hour (3 Hz), this 24-jewel self-winding caliber harnesses the kinetic energy of the wearer’s wrist to wind the mainspring, delivering approximately \u003c\/span\u003e\u003cspan class=\"citation-1487\"\u003e41 hours of autonomous power reserve\u003c\/span\u003e\u003cspan class=\"citation-1487 citation-end-1487\"\u003e on a full wind.\u003csup class=\"superscript\" data-turn-source-index=\"10\"\u003e\u003c!----\u003e\u003c\/sup\u003e\u003c\/span\u003e \u003cspan class=\"citation-1486 citation-end-1486\"\u003eDesigned purposefully without a calendar mechanism to preserve dial symmetry and the purity of the open-heart layout, the caliber features both automatic self-winding and manual hand-winding capabilities, along with a hacking seconds (stop-seconds) mechanism that halts the seconds hand when the crown is pulled out for down-to-the-second time synchronization.\u003csup class=\"superscript\" data-turn-source-index=\"11\"\u003e\u003c!----\u003e\u003c\/sup\u003e\u003c\/span\u003e \u003cspan class=\"citation-1485\"\u003eBuilt with Seiko’s proprietary \u003c\/span\u003e\u003cspan class=\"citation-1485\"\u003eDiashock\u003c\/span\u003e\u003cspan class=\"citation-1485\"\u003e shock-absorbing architecture, the movement delivers dependable stability rated to a factory precision tolerance of \u003c\/span\u003e\u003cspan class=\"citation-1485\"\u003e+45 to -35 seconds per day\u003c\/span\u003e\u003cspan class=\"citation-1485\"\u003e and incorporates \u003c\/span\u003e\u003cspan class=\"citation-1485\"\u003eJIS Class 1 magnetic resistance (4,800 A\/m)\u003c\/span\u003e\u003cspan class=\"citation-1485 citation-end-1485\"\u003e, protecting timekeeping accuracy against daily electromagnetic exposure from smartphones and laptops.\u003csup class=\"superscript\" data-turn-source-index=\"12\"\u003e\u003c!----\u003e\u003c\/sup\u003e\u003c\/span\u003e \u003c!----\u003e\u003c!----\u003e\u003c!----\u003e\u003c!----\u003e\u003c!----\u003e\u003c!----\u003e\u003c!----\u003e\u003c!----\u003e\u003c!----\u003e\u003cspan class=\"citation-1484\"\u003eThe case is engineered with versatile, contemporary dress-sports proportions, measuring an official \u003c\/span\u003e\u003cspan class=\"citation-1484\"\u003e40.0mm in case diameter\u003c\/span\u003e\u003cspan class=\"citation-1484\"\u003e with a case profile thickness of \u003c\/span\u003e\u003cspan class=\"citation-1484\"\u003e11.8mm\u003c\/span\u003e\u003cspan class=\"citation-1484\"\u003e, a compact \u003c\/span\u003e\u003cspan class=\"citation-1484\"\u003e46.2mm lug-to-lug distance\u003c\/span\u003e\u003cspan class=\"citation-1484\"\u003e, and a standard \u003c\/span\u003e\u003cspan class=\"citation-1484\"\u003e20mm lug width\u003c\/span\u003e\u003cspan class=\"citation-1484 citation-end-1484\"\u003e, delivering an ergonomic, flush drape on wrists of all sizes.\u003csup class=\"superscript\" data-turn-source-index=\"13\"\u003e\u003c!----\u003e\u003c\/sup\u003e\u003c\/span\u003e \u003cspan class=\"citation-1483 citation-end-1483\"\u003eThe solid 316L stainless steel case architecture combines vertical hairline satin brushing across the upper lugs with mirror-polished case flanks, contrasted by the warm yellow gold-plated fixed bezel.\u003csup class=\"superscript\" data-turn-source-index=\"14\"\u003e\u003c!----\u003e\u003c\/sup\u003e\u003c\/span\u003e \u003cspan class=\"citation-1482\"\u003eDial protection is provided by a high-grade flat \u003c\/span\u003e\u003cspan class=\"citation-1482\"\u003eHardlex crystal\u003c\/span\u003e\u003cspan class=\"citation-1482 citation-end-1482\"\u003e engineered to withstand everyday impacts and surface abrasions.\u003csup class=\"superscript\" data-turn-source-index=\"15\"\u003e\u003c!----\u003e\u003c\/sup\u003e\u003c\/span\u003e \u003cspan class=\"citation-1481\"\u003eBuilt for dependable everyday resilience, the watch features an ergonomic fluted pull-out crown at 3 o'clock and an exhibition see-through screw-down caseback that allows the wearer to view the mechanical balance and oscillating rotor, while securing an impressive \u003c\/span\u003e\u003cspan class=\"citation-1481\"\u003e10-bar (100 meters \/ 330 ft) water resistance rating\u003c\/span\u003e\u003cspan class=\"citation-1481 citation-end-1481\"\u003e, making it fully resilient against heavy rain, accidental splashes, and swimming.\u003csup class=\"superscript\" data-turn-source-index=\"16\"\u003e\u003c!----\u003e\u003c\/sup\u003e\u003c\/span\u003e \u003cspan class=\"citation-1480 citation-end-1480\"\u003eThe timepiece comes completed on an integrated two-tone solid stainless steel multi-link construction featuring brushed outer links and polished yellow gold-plated center accents, secured by a sturdy one-push three-fold deployment clasp with an easy-adjustment sizing system.\u003csup class=\"superscript\" data-turn-source-index=\"17\"\u003e\u003c!----\u003e\u003c\/sup\u003e\u003c\/span\u003e\u003c\/p\u003e","brand":"MonaWatch","offers":[{"title":"Default Title","offer_id":67704747491642,"sku":"HFB004J","price":1235.0,"currency_code":"AED","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0920\/5858\/3354\/files\/NewProject_83f1da24-05ab-476e-99eb-d2bbc14a3ed7.webp?v=1792049391","url":"https:\/\/www.monawatch.com\/products\/seiko-selection-open-heart-hfb004j-mens-watch","provider":"MonaWatch","version":"1.0","type":"link"}