{"id":68995,"date":"2026-06-09T12:36:57","date_gmt":"2026-06-09T10:36:57","guid":{"rendered":"https:\/\/ora24.gr\/?post_type=product&p=68995"},"modified":"2026-06-09T17:03:53","modified_gmt":"2026-06-09T15:03:53","slug":"el-primero-chronomaster-xxt-45mm-power-reserve-open-back-silver-open-heart-full-set","status":"publish","type":"product","link":"https:\/\/ora24.gr\/el\/product\/el-primero-chronomaster-xxt-45mm-power-reserve-open-back-silver-open-heart-full-set\/","title":{"rendered":"El Primero Chronomaster XXT 45mm Power Reserve Open Back Silver Open Heart Full Set"},"content":{"rendered":"
\u00a0 The <\/span>Zenith El Primero Chronomaster XXT Open Power Reserve 45mm<\/strong> (frequently designated under reference series like 03.1260.4021<\/a><\/span>) is a bold, historically significant luxury timepiece originating from the Thierry Nataf era of Zenith in the mid-2000s. Known for its substantial 45mm diameter<\/strong>, avant-garde open-heart dial, and legendary high-beat movement, it remains a distinctive choice for luxury watch enthusiasts.<\/pre>\n
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    The \"Open Heart\" Cutout<\/strong>: Located between the 9 and 11 o'clock positions, the dial is purposefully paired down with skeletonized bridges to expose the escapement, balance wheel, and hairspring assembly in high-beat motion from the front.<\/span>\u00a0<\/pre>\n<\/li>\n
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    The Open Back<\/strong>: True to its name, a scratch-resistant sapphire crystal display back<\/strong> reveals the intricate execution of the movement from behind, showcasing a rotor decorated with circular C\u00f4tes de Gen\u00e8ve, engine-turned perlage, and contrasting blued screws.<\/span><\/pre>\n<\/li>\n
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    Baroque-Style Case Architecture<\/strong>: The high-polish case stands out due to its fluted, tiered lugs and a triple-stepped \"triple gadroon\" bezel, projecting an Art Deco aesthetic.<\/span>\u00a0<\/pre>\n<\/li>\n
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    Complex Dial Patterning<\/strong>: The face features multiple finishes including concentric circular graining, applied Roman numeral indices, and a stamped radial guilloch\u00e9 pattern.<\/span>\u00a0<\/pre>\n<\/li>\n
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    Constant Seconds Functionality<\/strong>: Because the cutout removes the traditional small-seconds sub-dial, a unique three-spoked pinion extension<\/strong> attached to the fourth wheel serves as the constant running seconds hand inside the open window.<\/span><\/pre>\n<\/li>\n
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    Case Dimensions<\/strong>: The watch features a 45mm diameter<\/strong> case, measuring 14.2mm in thickness<\/strong> and 53.5mm from lug-to-lug<\/strong>, giving it an imposing and highly legible wrist presence.<\/span>\u00a0<\/pre>\n<\/li>\n
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    The Movement<\/strong>: Powered by the automatic Zenith Caliber El Primero 4021<\/strong>, a legendary column-wheel integrated chronograph movement composed of 248 parts, operating at a signature high frequency of 36,000 vibrations per hour (5Hz)<\/strong>.<\/span>\u00a0<\/pre>\n<\/li>\n
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    Power Reserve<\/strong>: Delivers a 50 to 52-hour power reserve<\/strong>, tracked visually via a dedicated fan-shaped indicator on the dial face.<\/span>\u00a0<\/pre>\n<\/li>\n
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    Water Resistance<\/strong>: Standard models offer a basic splash-ready 30 meters (3 ATM)<\/strong> of water resistance.<\/span><\/pre>\n<\/li>\n<\/ul>\n","protected":false},"excerpt":{"rendered":"
    \u00a0 The Zenith El Primero Chronomaster XXT Open Power Reserve 45mm (frequently designated under reference series like 03.1260.4021) is a bold, historically significant luxury timepiece originating from the Thierry Nataf era of Zenith in the mid-2000s. Known for its substantial 45mm diameter, avant-garde open-heart dial, and legendary high-beat movement, it remains a distinctive choice for […]<\/p>\n","protected":false},"featured_media":69018,"comment_status":"open","ping_status":"closed","template":"","meta":[],"product_cat":[1158,4571,1177],"product_tag":[1197],"class_list":{"0":"post-68995","1":"product","2":"type-product","3":"status-publish","4":"has-post-thumbnail","6":"product_cat-our-watches","7":"product_cat-men","8":"product_cat-zenith","9":"product_tag-homepage","10":"pa_box-papers-box-papers-and-1-year-warranty","11":"pa_bracelet-leather-strap","12":"pa_brand-zenith","13":"pa_case-stainless-steel","14":"pa_condition-excellent","15":"pa_dial-silver","16":"pa_diameter-45mm","17":"pa_functions-date","18":"pa_functions-chronograph","19":"pa_movement-automatic","20":"pa_reference-number-03-1260-4021","21":"pa_year-2-422","23":"first","24":"instock","25":"sale","26":"shipping-taxable","27":"purchasable","28":"product-type-simple"},"_links":{"self":[{"href":"https:\/\/ora24.gr\/el\/wp-json\/wp\/v2\/product\/68995"}],"collection":[{"href":"https:\/\/ora24.gr\/el\/wp-json\/wp\/v2\/product"}],"about":[{"href":"https:\/\/ora24.gr\/el\/wp-json\/wp\/v2\/types\/product"}],"replies":[{"embeddable":true,"href":"https:\/\/ora24.gr\/el\/wp-json\/wp\/v2\/comments?post=68995"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/ora24.gr\/el\/wp-json\/wp\/v2\/media\/69018"}],"wp:attachment":[{"href":"https:\/\/ora24.gr\/el\/wp-json\/wp\/v2\/media?parent=68995"}],"wp:term":[{"taxonomy":"product_cat","embeddable":true,"href":"https:\/\/ora24.gr\/el\/wp-json\/wp\/v2\/product_cat?post=68995"},{"taxonomy":"product_tag","embeddable":true,"href":"https:\/\/ora24.gr\/el\/wp-json\/wp\/v2\/product_tag?post=68995"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}