Around 1968, Heuer introduced its very first GMT chronograph model, which used a variation of the short run fourth execution Autavia dial in a screw-back case. A noticeable feature of this particular type of dial is the lume hour Tritium markers that are applied directly to the dial, reminiscent of the very first Autavia watches (but without numerals). The 24 hour hand enabled the reading of a second time zone in conjunction with the bezel. This new feature was obtained by using a modified Valjoux 72 calibre, known as the Valjoux 724 movement.

The timepiece illustrated here in these pages is considered one of the "Holy Grails" of Heuer collecting, and has seldom been seen, in fact it may be the only time one has appeared at a major auction house.

Research suggests only 8 have been found to date and all of them within a tight serial number range covering approximately 70 numbers, from100012 to 10008x. This example is the earliest known survivor of this tiny batch and may be the best preserved, with beautiful patina on the dial and hand lume and a mint condition bezel. The rarest Heuer GMT ever produced in stunning condition, what's not to like?