{"product_id":"vintage-eterna-matic-kontiki-20-watch-day-date-37mm-all-s-s-original-bracelet","title":"Vintage Eterna-Matic Kontiki 20 Watch Day\/Date 37mm ALL S.S. - Original Bracelet","description":"\u003ch2\u003eWatch Overview\u003c\/h2\u003e\n\u003cp\u003eETERNA-MATIC Watch Co. — “First gents automatic-family with ball-bearing rotor”.\u003c\/p\u003e\n\u003cp\u003eOffered here is a collectible vintage Eterna-Matic KonTiki 20 automatic wristwatch, dating from the 1970s.\u003c\/p\u003e\n\u003cp\u003eThe Eterna-Matic movement system, introduced by Eterna in 1948, became one of the brand’s most important innovations. It utilized five strategically placed ball bearings to support the automatic winding rotor, significantly reducing friction and improving winding efficiency while minimizing wear on internal components. This innovation became so influential that the five-ball-bearing logo remains part of Eterna’s identity today.\u003c\/p\u003e\n\u003cp\u003eThe KonTiki line was inspired by Thor Heyerdahl’s famous 1947 Kon-Tiki expedition across the Pacific Ocean. Eterna supplied watches for the journey, and the success of the expedition helped establish the model name as one associated with durability. By the 1970s, models such as the KonTiki 20 blended robust automatic movements with modern case design.\u003c\/p\u003e\n\u003cp\u003eIt is powered by the Eterna-Matic automatic movement caliber ETA 2836, featuring 25 jewels, a sweep seconds hand, and a quick-set day-date display. This Swiss-made movement operates at 28,800 vph and offers an approximate 40-hour power reserve.\u003c\/p\u003e\n\u003cp\u003eThe watch features a light silver-green dial accented by applied baton hour markers, printed minute track, luminous plots, and matching baton hands. The day-date display is positioned at 3 o’clock.\u003c\/p\u003e\n\u003cp\u003eHoused in a 37mm stainless steel tonneau-style case with a fixed smooth bezel and signed KonTiki caseback medallion. It is fitted with its original stainless steel bracelet.\u003c\/p\u003e\n\u003cp\u003eFully inspected and authenticated, the watch remains in very good vintage condition consistent with its age and is ready to wear and enjoy.\u003c\/p\u003e\n\u003ch2\u003eProduct Details\u003c\/h2\u003e\n\u003ch3\u003eGeneral Specifications\u003c\/h3\u003e\n\u003cul style=\"list-style-type: disc; padding-left: 20px; margin-bottom: 12px;\"\u003e\n\u003cli\u003e\n\u003cstrong\u003eBrand:\u003c\/strong\u003e Eterna-Matic\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eType:\u003c\/strong\u003e Wristwatch\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eModel:\u003c\/strong\u003e KonTiki 20\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eYear \/ Era:\u003c\/strong\u003e 1970s – Vintage\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eGender:\u003c\/strong\u003e Men's\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eCountry of Manufacture:\u003c\/strong\u003e Switzerland\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003ch3\u003eDial \u0026amp; Display\u003c\/h3\u003e\n\u003cul style=\"list-style-type: disc; padding-left: 20px; margin-bottom: 12px;\"\u003e\n\u003cli\u003e\n\u003cstrong\u003eDisplay:\u003c\/strong\u003e Analog\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eDial Color:\u003c\/strong\u003e Light Silver-Green\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eFeatures:\u003c\/strong\u003e Baton hour markers, minute track, sweep-seconds hand, day\/date indicator\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003ch3\u003eMovement\u003c\/h3\u003e\n\u003cul style=\"list-style-type: disc; padding-left: 20px; margin-bottom: 12px;\"\u003e\n\u003cli\u003e\n\u003cstrong\u003eMovement Type:\u003c\/strong\u003e Automatic \/ Self-Winding\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eCaliber:\u003c\/strong\u003e ETA 2836\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eJewels:\u003c\/strong\u003e 25 Jewels\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eMovement Functions:\u003c\/strong\u003e\n\u003cul style=\"list-style-type: disc; padding-left: 20px; margin-bottom: 8px;\"\u003e\n\u003cli\u003eSweep seconds\u003c\/li\u003e\n\u003cli\u003eQuick-set day\/date display\u003c\/li\u003e\n\u003cli\u003eEterna-Matic ball-bearing rotor system\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003ePower Reserve:\u003c\/strong\u003e Approx. 40 Hours\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eFrequency:\u003c\/strong\u003e 28,800 vph\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003ch3\u003eCase \u0026amp; Band\u003c\/h3\u003e\n\u003cul style=\"list-style-type: disc; padding-left: 20px; margin-bottom: 12px;\"\u003e\n\u003cli\u003e\n\u003cstrong\u003eCase Material:\u003c\/strong\u003e Stainless Steel\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eCase Shape:\u003c\/strong\u003e Tonneau \/ Barrel\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eBezel:\u003c\/strong\u003e Fixed, Smooth\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eCase Back:\u003c\/strong\u003e Screw-Back\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eBracelet:\u003c\/strong\u003e Original Stainless Steel Bracelet\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eMax Wrist Size:\u003c\/strong\u003e Approx. 8\"\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003ch3\u003eCase Measurements (mm)\u003c\/h3\u003e\n\u003cul style=\"list-style-type: disc; padding-left: 20px; margin-bottom: 12px;\"\u003e\n\u003cli\u003e\n\u003cstrong\u003eCase Size:\u003c\/strong\u003e 37\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eCase Diameter w\/Crown:\u003c\/strong\u003e 40\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eCase Lug to Lug:\u003c\/strong\u003e 42\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eCase Thickness:\u003c\/strong\u003e 11.7\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eBand Width:\u003c\/strong\u003e 25.4\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003ch2\u003eAdditional Info\u003c\/h2\u003e\n\u003cul style=\"list-style-type: disc; padding-left: 20px; margin-bottom: 12px;\"\u003e\n\u003cli\u003e\n\u003cstrong\u003eBox \u0026amp; Papers:\u003c\/strong\u003e No\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eCondition:\u003c\/strong\u003e The watch is in very good vintage condition, showing signs of wear consistent with age and normal use.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eNotes:\u003c\/strong\u003e Fully inspected and authenticated by our in-house watchmaker. Ready to wear.\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003ch2\u003eAbout Second Hand Horology\u003c\/h2\u003e\n\u003cp\u003eAt SECOND HAND HOROLOGY, we offer a curated selection of watches ranging from vintage to modern, including both brand-new and pre-owned timepieces. We’re committed to quality, accuracy, and integrity. Our listings feature:\u003c\/p\u003e\n\u003cp\u003eProfessional, unedited photography and clear, transparent descriptions. Every watch is thoroughly inspected and securely packaged to ensure a confident, seamless buying experience.\u003c\/p\u003e\n\u003cp\u003eWe also warmly invite you to visit our physical shop and explore the collection in person.\u003c\/p\u003e\n\u003ch2\u003eContact Us\u003c\/h2\u003e\n\u003cp\u003eWe appreciate you checking out our listing! Don’t hesitate to reach out with questions, offers, or just to talk watches — we love what we do and enjoy connecting with fellow enthusiasts.\u003c\/p\u003e\n\u003cp\u003eThank you for your business—we truly appreciate your support and look forward to serving you again in the future!\u003c\/p\u003e\n\u003cp\u003eWA-7080\u003c\/p\u003e","brand":"Eterna","offers":[{"title":"Default Title","offer_id":47655279198402,"sku":"WA-7080","price":1200.0,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0577\/7027\/9106\/files\/DSC8608-EDIT..jpg?v=1778612480","url":"https:\/\/secondhandhorology.com\/products\/vintage-eterna-matic-kontiki-20-watch-day-date-37mm-all-s-s-original-bracelet","provider":"SECOND HAND HOROLOGY","version":"1.0","type":"link"}