Heuer 2446c GMT Mark4 1960s

The Heuer AUTAVIA Ref. 2446 series stands among the most iconic chronographs of the 1960s. Within this legendary lineage, the Ref. 2446C-GMT Mark 4—equipped with the Valjoux Caliber 724 GMT movement—is one of the rarest and most sought-after variants ever produced.

The defining characteristic of the Mark 4 is its exclusive all-red handset. From the red-tipped triangular 24-hour GMT hand to the wide baton hour and minute hands and the central chronograph seconds hand, every functional hand is finished in vivid red. Beyond the practicality of its 24-hour GMT display, this bold and unmistakable design has made the Mark 4 one of the most celebrated icons in the world of vintage Heuer.

Measuring approximately 40mm in diameter, the watch features a robust screw-back case complemented by a red and blue 24-hour GMT bezel. Beautifully faded through decades of natural aging, the bezel harmonizes perfectly with the matte black dial and warm tritium lume, creating the unmistakable character that only a genuine vintage timepiece can possess.

Powering the watch is the legendary Valjoux Caliber 724, developed from the renowned Valjoux 72 with the addition of a GMT complication. Its column-wheel chronograph architecture delivers the crisp yet remarkably smooth pusher action for which classic Valjoux movements are celebrated, offering a deeply satisfying mechanical experience every time the chronograph is engaged.

Examples are exceptionally scarce, and watches retaining their original condition become increasingly difficult to find with each passing year. The Ref. 2446C-GMT Mark 4 occupies a truly special place in the history of vintage Heuer and remains one of the most coveted GMT chronographs among serious collectors.

Joseph Siffert — The Man Who Made AUTAVIA a Legend

No discussion of this reference would be complete without Joseph Siffert, the legendary Swiss Formula One driver.

In 1968, Siffert signed a sponsorship agreement with Heuer and became one of the most recognizable figures in international motorsport, competing not only in Formula One but also as a Porsche factory driver. Tragically, on October 24, 1971, he lost his life at the age of just 35 following an accident during the Victory Race at Brands Hatch, a loss that shocked the motorsport world.

When Heuer introduced one of the world's first automatic chronographs—the Chronomatic (Caliber 11)—in 1969, then-CEO Jack Heuer presented a Monaco to his friend Steve McQueen and an AUTAVIA to Joseph Siffert. Siffert wore the AUTAVIA during competition, and the image of the watch on his wrist became inseparable from his racing career. Even today, certain references are affectionately known as the "Siffert Autavia," a testament to the enduring connection between the driver and the model.

The name AUTAVIA itself dates back to 1933, combining the words AUTOmobile and AVIAtion for Heuer's dashboard timers. In 1962, the name was reborn as a wristwatch with the introduction of the first AUTAVIA Ref. 2446.

Within that historic lineage, the Ref. 2446C-GMT—powered by the Valjoux Caliber 724 and distinguished by the Mark 4's exclusive all-red handset—represents one of the ultimate expressions of the first-generation AUTAVIA.

Combining authentic racing heritage with the unmistakable beauty of a well-preserved vintage watch, it continues to captivate collectors around the world more than half a century after its introduction.

- wrist size in our picture is 17cm circumference -