This is a vintage and very rare 36mm. Heuer Carrera reference 2447 measuring 36mm. and unmolested. This version has a rare and early silver dial with very rare eggshell toned sub-registers. The dial, lume and hands are original. The caliber 72 manual winding chronograph movement is running flawlessly after a very recent servicing. This is a very desireable vintage Heuer.