{"id":69421,"date":"2026-06-17T14:17:26","date_gmt":"2026-06-17T12:17:26","guid":{"rendered":"https:\/\/ora24.gr\/?post_type=product&#038;p=69421"},"modified":"2026-06-17T14:17:27","modified_gmt":"2026-06-17T12:17:27","slug":"chronomaster-open-heart-0312604039-automatic-big-date-power-reserve-45mm-black-dial-full-set","status":"publish","type":"product","link":"https:\/\/ora24.gr\/el\/product\/chronomaster-open-heart-0312604039-automatic-big-date-power-reserve-45mm-black-dial-full-set\/","title":{"rendered":"Chronomaster Open Heart 0312604039 Automatic Big Date Power Reserve 45mm Black Dial Full Set"},"content":{"rendered":"<pre>\u00a0 The <strong class=\"Yjhzub\" data-sfc-root=\"c\" data-sfc-cb=\"\" data-complete=\"true\" data-processed=\"true\" data-copy-service-computed-style=\"font-family: &quot;Google Sans&quot;, Arial, sans-serif; font-size: 16px; font-weight: 600; margin: 0px; text-decoration: none; border-bottom: 0px rgb(10, 10, 10);\">Zenith Chronomaster XXT Open Grande Date (Reference 03.1260.4039\/21.C505)<!--TgQPHd||[]--><\/strong> is a prominent, mechanically complex luxury timepiece originating from the bold design era of the mid-2000s under former Zenith CEO Terry Nataf. Famous for its partial skeletonization and high-frequency performance, it offers a \"tourbillon-like\" visual entertainment at a fraction of the cost.<\/pre>\n<ul>\n<li class=\"Z1qcYe\" data-sfc-cp=\"\" data-sfc-root=\"ep\" data-sfc-cb=\"\" data-hveid=\"CAIIAAgOEAE\" data-complete=\"true\" data-sae=\"\" data-copy-service-computed-style=\"font-family: &quot;Google Sans&quot;, Arial, sans-serif; font-size: 16px; font-weight: 400; margin: 0px 0px 12px; text-decoration: none; border-bottom: 0px rgb(10, 10, 10);\">\n<pre><span class=\"T286Pc\" data-sfc-cp=\"\" data-sfc-root=\"c\" data-sfc-cb=\"\" data-complete=\"true\" data-copy-service-computed-style=\"font-family: &quot;Google Sans&quot;, Arial, sans-serif; font-size: 16px; font-weight: 400; margin: 0px; text-decoration: none; border-bottom: 0px rgb(10, 10, 10);\"><strong class=\"Yjhzub\" data-sfc-root=\"c\" data-sfc-cb=\"\" data-complete=\"true\" data-copy-service-computed-style=\"font-family: &quot;Google Sans&quot;, Arial, sans-serif; font-size: 16px; font-weight: 600; margin: 0px; text-decoration: none; border-bottom: 0px rgb(10, 10, 10);\">Case Size &amp; Dimensions<!--TgQPHd||[]--><\/strong>: It features a bold <strong class=\"Yjhzub\" data-sfc-root=\"c\" data-sfc-cb=\"\" data-complete=\"true\" data-copy-service-computed-style=\"font-family: &quot;Google Sans&quot;, Arial, sans-serif; font-size: 16px; font-weight: 600; margin: 0px; text-decoration: none; border-bottom: 0px rgb(10, 10, 10);\">45mm diameter<!--TgQPHd||[]--><\/strong> stainless steel case, with a thickness of roughly 16.5mm and a lug-to-lug span of 53.5mm.<!--TgQPHd||[]--><\/span>\u00a0<span data-copy-service-computed-style=\"font-family: &quot;Google Sans&quot;, Arial, sans-serif; font-size: 16px; font-weight: 400; margin: 0px; text-decoration: none; border-bottom: 0px rgb(10, 10, 10);\"><!--TgQPHd||[]--><\/span><!--TgQPHd||[]--><\/pre>\n<\/li>\n<li class=\"Z1qcYe\" data-sfc-cp=\"\" data-sfc-root=\"ep\" data-sfc-cb=\"\" data-hveid=\"CAIIAAgOEAc\" data-complete=\"true\" data-sae=\"\" data-copy-service-computed-style=\"font-family: &quot;Google Sans&quot;, Arial, sans-serif; font-size: 16px; font-weight: 400; margin: 0px 0px 12px; text-decoration: none; border-bottom: 0px rgb(10, 10, 10);\">\n<pre><span class=\"T286Pc\" data-sfc-cp=\"\" data-sfc-root=\"c\" data-sfc-cb=\"\" data-complete=\"true\" data-copy-service-computed-style=\"font-family: &quot;Google Sans&quot;, Arial, sans-serif; font-size: 16px; font-weight: 400; margin: 0px; text-decoration: none; border-bottom: 0px rgb(10, 10, 10);\"><strong class=\"Yjhzub\" data-sfc-root=\"c\" data-sfc-cb=\"\" data-complete=\"true\" data-copy-service-computed-style=\"font-family: &quot;Google Sans&quot;, Arial, sans-serif; font-size: 16px; font-weight: 600; margin: 0px; text-decoration: none; border-bottom: 0px rgb(10, 10, 10);\">The Movement<!--TgQPHd||[]--><\/strong>: Powered by the legendary in-house <strong class=\"Yjhzub\" data-sfc-root=\"c\" data-sfc-cb=\"\" data-complete=\"true\" data-copy-service-computed-style=\"font-family: &quot;Google Sans&quot;, Arial, sans-serif; font-size: 16px; font-weight: 600; margin: 0px; text-decoration: none; border-bottom: 0px rgb(10, 10, 10);\">Zenith El Primero Caliber 4039<!--TgQPHd||[]--><\/strong>. This automatic integrated column-wheel chronograph beats at a high-frequency of 36,000 vibrations per hour (10 beats per second), providing an ultra-smooth sweeping chronograph hand.<!--TgQPHd||[]--><\/span>\u00a0<span data-copy-service-computed-style=\"font-family: &quot;Google Sans&quot;, Arial, sans-serif; font-size: 16px; font-weight: 400; margin: 0px; text-decoration: none; border-bottom: 0px rgb(10, 10, 10);\"><!--TgQPHd||[]--><\/span><!--TgQPHd||[]--><\/pre>\n<\/li>\n<li class=\"Z1qcYe\" data-sfc-cp=\"\" data-sfc-root=\"ep\" data-sfc-cb=\"\" data-hveid=\"CAIIAAgOEA0\" data-complete=\"true\" data-sae=\"\" data-copy-service-computed-style=\"font-family: &quot;Google Sans&quot;, Arial, sans-serif; font-size: 16px; font-weight: 400; margin: 0px 0px 12px; text-decoration: none; border-bottom: 0px rgb(10, 10, 10);\">\n<pre><span class=\"T286Pc\" data-sfc-cp=\"\" data-sfc-root=\"c\" data-sfc-cb=\"\" data-complete=\"true\" data-copy-service-computed-style=\"font-family: &quot;Google Sans&quot;, Arial, sans-serif; font-size: 16px; font-weight: 400; margin: 0px; text-decoration: none; border-bottom: 0px rgb(10, 10, 10);\"><strong class=\"Yjhzub\" data-sfc-root=\"c\" data-sfc-cb=\"\" data-complete=\"true\" data-copy-service-computed-style=\"font-family: &quot;Google Sans&quot;, Arial, sans-serif; font-size: 16px; font-weight: 600; margin: 0px; text-decoration: none; border-bottom: 0px rgb(10, 10, 10);\">Power Reserve<!--TgQPHd||[]--><\/strong>: Equipped with a 50 to 55-hour power reserve, monitored via a dedicated sector scale indicator located on the lower half of the dial.<\/span><\/pre>\n<\/li>\n<li class=\"Z1qcYe\" data-sfc-cp=\"\" data-sfc-root=\"ep\" data-sfc-cb=\"\" data-hveid=\"CAIIAAgbEAE\" data-complete=\"true\" data-sae=\"\" data-copy-service-computed-style=\"font-family: &quot;Google Sans&quot;, Arial, sans-serif; font-size: 16px; font-weight: 400; margin: 0px 0px 12px; text-decoration: none; border-bottom: 0px rgb(10, 10, 10);\">\n<pre><span class=\"T286Pc\" data-sfc-cp=\"\" data-sfc-root=\"c\" data-sfc-cb=\"\" data-complete=\"true\" data-copy-service-computed-style=\"font-family: &quot;Google Sans&quot;, Arial, sans-serif; font-size: 16px; font-weight: 400; margin: 0px; text-decoration: none; border-bottom: 0px rgb(10, 10, 10);\"><strong class=\"Yjhzub\" data-sfc-root=\"c\" data-sfc-cb=\"\" data-complete=\"true\" data-copy-service-computed-style=\"font-family: &quot;Google Sans&quot;, Arial, sans-serif; font-size: 16px; font-weight: 600; margin: 0px; text-decoration: none; border-bottom: 0px rgb(10, 10, 10);\">Open-Heart Cutaway<!--TgQPHd||[]--><\/strong>: Positioned between the 8 and 12 o'clock marks, a meticulously framed dial window exposes the beating escapement, balance wheel, and a unique tri-spoke constant small seconds pinion.<!--TgQPHd||[]--><\/span><span data-copy-service-computed-style=\"font-family: &quot;Google Sans&quot;, Arial, sans-serif; font-size: 16px; font-weight: 400; margin: 0px; text-decoration: none; border-bottom: 0px rgb(10, 10, 10);\"><!--TgQPHd||[]--><\/span><!--TgQPHd||[]--><\/pre>\n<\/li>\n<li class=\"Z1qcYe\" data-sfc-cp=\"\" data-sfc-root=\"ep\" data-sfc-cb=\"\" data-hveid=\"CAIIAAgbEAI\" data-complete=\"true\" data-sae=\"\" data-copy-service-computed-style=\"font-family: &quot;Google Sans&quot;, Arial, sans-serif; font-size: 16px; font-weight: 400; margin: 0px 0px 12px; text-decoration: none; border-bottom: 0px rgb(10, 10, 10);\">\n<pre><span class=\"T286Pc\" data-sfc-cp=\"\" data-sfc-root=\"c\" data-sfc-cb=\"\" data-complete=\"true\" data-copy-service-computed-style=\"font-family: &quot;Google Sans&quot;, Arial, sans-serif; font-size: 16px; font-weight: 400; margin: 0px; text-decoration: none; border-bottom: 0px rgb(10, 10, 10);\"><strong class=\"Yjhzub\" data-sfc-root=\"c\" data-sfc-cb=\"\" data-complete=\"true\" data-copy-service-computed-style=\"font-family: &quot;Google Sans&quot;, Arial, sans-serif; font-size: 16px; font-weight: 600; margin: 0px; text-decoration: none; border-bottom: 0px rgb(10, 10, 10);\">Grande Date (Big Date)<!--TgQPHd||[]--><\/strong>: Located near the upper right quadrant, this complication utilizes a dual-disk system. Expert reviewers highlight the mechanism's dual sapphire disk overlays as a highly entertaining and distinct mechanical layout.<!--TgQPHd||[]--><\/span><span data-copy-service-computed-style=\"font-family: &quot;Google Sans&quot;, Arial, sans-serif; font-size: 16px; font-weight: 400; margin: 0px; text-decoration: none; border-bottom: 0px rgb(10, 10, 10);\"><!--TgQPHd||[]--><\/span><!--TgQPHd||[]--><\/pre>\n<\/li>\n<li class=\"Z1qcYe\" data-sfc-cp=\"\" data-sfc-root=\"ep\" data-sfc-cb=\"\" data-hveid=\"CAIIAAgbEAM\" data-complete=\"true\" data-sae=\"\" data-copy-service-computed-style=\"font-family: &quot;Google Sans&quot;, Arial, sans-serif; font-size: 16px; font-weight: 400; margin: 0px 0px 12px; text-decoration: none; border-bottom: 0px rgb(10, 10, 10);\">\n<pre><span class=\"T286Pc\" data-sfc-cp=\"\" data-sfc-root=\"c\" data-sfc-cb=\"\" data-complete=\"true\" data-copy-service-computed-style=\"font-family: &quot;Google Sans&quot;, Arial, sans-serif; font-size: 16px; font-weight: 400; margin: 0px; text-decoration: none; border-bottom: 0px rgb(10, 10, 10);\"><strong class=\"Yjhzub\" data-sfc-root=\"c\" data-sfc-cb=\"\" data-complete=\"true\" data-copy-service-computed-style=\"font-family: &quot;Google Sans&quot;, Arial, sans-serif; font-size: 16px; font-weight: 600; margin: 0px; text-decoration: none; border-bottom: 0px rgb(10, 10, 10);\">Dial Styling<!--TgQPHd||[]--><\/strong>: Features a striking <strong class=\"Yjhzub\" data-sfc-root=\"c\" data-sfc-cb=\"\" data-complete=\"true\" data-copy-service-computed-style=\"font-family: &quot;Google Sans&quot;, Arial, sans-serif; font-size: 16px; font-weight: 600; margin: 0px; text-decoration: none; border-bottom: 0px rgb(10, 10, 10);\">black Guilloche-textured dial<!--TgQPHd||[]--><\/strong> adorned with elegant, radially arrayed blackened or silver-tone applied Roman numeral markers.<!--TgQPHd||[]--><\/span><span data-copy-service-computed-style=\"font-family: &quot;Google Sans&quot;, Arial, sans-serif; font-size: 16px; font-weight: 400; margin: 0px; text-decoration: none; border-bottom: 0px rgb(10, 10, 10);\"><!--TgQPHd||[]--><\/span><!--TgQPHd||[]--><\/pre>\n<\/li>\n<li class=\"Z1qcYe\" data-sfc-cp=\"\" data-sfc-root=\"ep\" data-sfc-cb=\"\" data-hveid=\"CAIIAAgbEAQ\" data-complete=\"true\" data-sae=\"\" data-copy-service-computed-style=\"font-family: &quot;Google Sans&quot;, Arial, sans-serif; font-size: 16px; font-weight: 400; margin: 0px 0px 12px; text-decoration: none; border-bottom: 0px rgb(10, 10, 10);\">\n<pre><span class=\"T286Pc\" data-sfc-cp=\"\" data-sfc-root=\"c\" data-sfc-cb=\"\" data-complete=\"true\" data-copy-service-computed-style=\"font-family: &quot;Google Sans&quot;, Arial, sans-serif; font-size: 16px; font-weight: 400; margin: 0px; text-decoration: none; border-bottom: 0px rgb(10, 10, 10);\"><strong class=\"Yjhzub\" data-sfc-root=\"c\" data-sfc-cb=\"\" data-complete=\"true\" data-copy-service-computed-style=\"font-family: &quot;Google Sans&quot;, Arial, sans-serif; font-size: 16px; font-weight: 600; margin: 0px; text-decoration: none; border-bottom: 0px rgb(10, 10, 10);\">Strap &amp; Hardware<!--TgQPHd||[]--><\/strong>: Outfitted on a premium 22mm black alligator leather strap pairing with a polished stainless steel double-deployment folding clasp.<\/span><\/pre>\n<\/li>\n<\/ul>","protected":false},"excerpt":{"rendered":"<p>\u00a0 The Zenith Chronomaster XXT Open Grande Date (Reference 03.1260.4039\/21.C505) is a prominent, mechanically complex luxury timepiece originating from the bold design era of the mid-2000s under former Zenith CEO Terry Nataf. Famous for its partial skeletonization and high-frequency performance, it offers a &#8220;tourbillon-like&#8221; visual entertainment at a fraction of the cost. Case Size &amp; [&hellip;]<\/p>\n","protected":false},"featured_media":69443,"comment_status":"open","ping_status":"closed","template":"","meta":[],"product_cat":[4571,1158,1177],"product_tag":[1197],"class_list":{"0":"post-69421","1":"product","2":"type-product","3":"status-publish","4":"has-post-thumbnail","6":"product_cat-men","7":"product_cat-our-watches","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-black","16":"pa_diameter-45mm","17":"pa_functions-chronograph","18":"pa_functions-day","19":"pa_functions-power-reserve","20":"pa_movement-automatic","21":"pa_reference-number-03-1260-4039-21-c505","22":"pa_year-2-548","24":"first","25":"instock","26":"shipping-taxable","27":"purchasable","28":"product-type-simple"},"_links":{"self":[{"href":"https:\/\/ora24.gr\/el\/wp-json\/wp\/v2\/product\/69421"}],"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=69421"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/ora24.gr\/el\/wp-json\/wp\/v2\/media\/69443"}],"wp:attachment":[{"href":"https:\/\/ora24.gr\/el\/wp-json\/wp\/v2\/media?parent=69421"}],"wp:term":[{"taxonomy":"product_cat","embeddable":true,"href":"https:\/\/ora24.gr\/el\/wp-json\/wp\/v2\/product_cat?post=69421"},{"taxonomy":"product_tag","embeddable":true,"href":"https:\/\/ora24.gr\/el\/wp-json\/wp\/v2\/product_tag?post=69421"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}