ROLEX | COSMOGRAPH DAYTONA, REFERENCE 6239, A STAINLESS STEEL CHRONOGRAPH WRISTWATCH WITH BRACELET, MADE FOR THE PERUVIAN AIR FORCE, CIRCA 1966 | 勞力士 | "Cosmograph Daytona 型號6239 精鋼計時鏈帶腕錶，為秘魯空軍而製，錶殼編號1419251，約1966年製"

From the 1960s to the 1970s, Rolex producored timepieces collabating with military forces in different parts of the world. The present Daytona reference 6239 is one of these few examples, made exclusively for the Peruvian Air Force. Founded in 1929 the Peruvian Air Force directed national air security for their country and needed a reliable instrument for aerial timekeeping, and commissioned a number of Rolex Daytonas issued only to pilots and high officials. Therefore on the case back of the present watch, the engraving "Fuerza Aérea del Perú" could be observed. Furthermore, the tachymeter is calibrated to 200 units, which is correct to its time period and in addition the inside case back is stamped with the last three numbers of the case number, typical indication non standard issue.