Welcome to my Top Chronographs Boutique! Zenith SA was started in 1865 by Georges Favre-Jacot at the age of 22, in Le Locle (canton of Neuchâtel), Switzerland. In the late 1960s there was a prestigious race to develop the world's first mechanical chronograph with automatic winding Heuer-Leonidas and Dubois Dépraz had initiated the secret “Project 99” to develop such a movement, bringing in Hamilton/Büren and Breitling. On March 3, 1969, this group presented their product under the name of “Chronomatic” ​​simultaneously in Geneva, New York, Hong Kong and Beirut. The barrel of the Chronomatic is wound by means of an eccentric weight segment, a concept called a “microrotor”. Realizing that this announcement was imminent, Zenith rushed to preempt them. Their Cal. 3019 "El Primero" movement (“The First”) was unveiled in a quiet press conference in Geneva on January 10 of the same year. They had begun developing their integrated automatic chronograph at the beginning of the decade, with the project stalled and restarted later. By late 1968, a few El Primero prototypes had been produced and these were shown to the world in January. It was not until late in 1969 that Zenith was able to produce customer-ready movements and watches. The development of the El Primero had already begun in 1967. While the Calibre 11 “Chronomatic” only made 19,800 semicycles, the El Primero oscillated with 36,000 semicycles, which was unusual for the time. This result is unsurpassed even today and has led many large watch manufacturers to equip its chronograph models with this unique movement. Among others, Rolex used it in their model Cosmograph Daytona, but here the amplitude was taken back to 28,800 A/h, see Rolex 4030; in the meantime Rolex has their own in-house made chronograph calibre, the Rolex 4130. The first model of the 'El Primero' was available in two versions Cal. 3019PHC had the unmistakable date display at the 4 00 location while Cal. 3019PHF featured the day, month and moon-phase indication. The weight segment in tungsten carbide registered even the smallest, otherwise not perceptible movements of the wearer's arm. The power reserve amounted to more than 50 hours, the weight segment was embellished by the company logo. The El Primero movement has a diameter of 30 mm and with only 6.5 mm is very flat. Due to its high oscillation rate, it is also the only chronograph movement, which permits a short-term measurement of 1/10 seconds. Other advantages are the instantaneous date change and a dry lubrication on molybdenum-sulfide basis. After twenty years Zenith incorporated a few modifications into the El Primero movement, which should increase its power and reduce the wear of some components. The winding of the chronograph and the operating the chronograph functions, such as zero reset, were simplified. One of the first pieces is exhibited in the Museum Château des Monts in Le Locle. Stylish and sophisticated, the offered iconic timepiece combines the traditional precision of the famed mechanical chronograph and a modern look of first-class materials. Movement: - in-house automatic caliber 400Z - column wheel chronograph - 31 jewels - power reserve: 50 hours - frequency: 36,000VpH (5Hz) - 278 components Case: - 316L stainless-steel, polished/fine brushed - 40mm excl. crown, 41,8mm incl. - 11,5mm thick - anti-reflective domed sapphire crystal Crown: - stainless steel, polished - pull/push with logo Bezel: fixed, polished stainless-steel Case-back: sapphire, see-through Dial: - black - polished hands and chic hour batons at 03:00, 06:00, 09:00 and 12:00 o'clock - silver printed Arabic numerals - minutes and seconds markers round the outer rim - date at 04:30 o'clock - three chronograph sub-dials: 30-minute counter at 03:00 o'clock 12 hours at 06:00 o'clock small seconds at 09:00 o'clock - chronograph central second hand Bracelet: - brand new black leather, alligator grain on cow - length: 21cm incl. wristwatch itself and extra link - width: 21mm by lugs, 18mm by clasp Clasp: - double folding "butterfly" - original Zenith - polished stainless steel - logo star and engraving Weight: 93 grams with extra link Water-resistant 5ATM/50meters, not useful for swimming and diving High recognition value. Distinctive design. Chic authentic Zenith wooden watch box (see pics). General professional pre-sale service was made in August 2024: the watch is keeping good time and working perfectly. Excellent condition, never worn: the wristwatch comes from luxury watch-shop showcase; that's why the strap is replaced with brand new one, alligator grain on cow (leather straps often suffer from temperature in shop windows due to powerful spotlights). My personal authenticity and quality warranty: you will get warranty card (as pictured), fully completed and signed on the back. Insured, registered shipping worldwide. Everything you see in my pics is included in the package that you'll receive. The offered El Primero chronograph is not attractive to cheapers chasing fashion: it is a treasure for connoisseurs and admirers! Lucky find for every watch lover: unworn Port Royal! NO EXTRA COSTS for EU Buyers!