Reference A277 was in production throughout the 1960s, with one notable evolution during its production. First series watches feature blued hands for the subsidiary counters, no luminous material on the chronographic second hand, a five-point star Zenith emblem on the crown, and the cal. 146H. Subsequently, the watch in its final form would feature bronzed hands for the subsidiary counters, luminous chronographic second hand, a four-point star on the crown, and the cal. 146HP.

The present example is a remarkable specimen of the second series, fully original and offered in superlative condition. The dial is simply flawless, and the case is in excellent condition. Most notably, the serial number 567D370, which is finely engraved to the outside of the caseback is still perfectly readable. This numbering system of three numbers followed by a letter followed again by three numbers was employed by Zenith beginning in the early 1960s with xxxAxxx until the 1970s, and numbers xxxExxx. The present watch was thus made in the late 1960s or early 1970s, perfectly matching the bracelet stamp “3 70”.

Offering an intriguing combination of condition, looks and professional vocation, this watch will delight the collector of vintage professional timepieces.