The present mid -20th century example is well preserved with a case that retains its strong proportions with a lovely aged dial with original luminous numerals the have turned a dark brown. The rotating bezel features an inclined 60unit scale and continually running chronograph hand, that rests to zero through the single button in the case. The oversize onion crown assured easy to grip when setting the watch with a gloved hand. While the 47.5mm case was necessary at the time for readability it would have been too large for the every day, when watches typically measured a mere 30-33mm. The present example has a Japanese inscription, which is confirmed the manufacturer, the watch was sold in 1956 to Hattori, the Longines retailer at the time and delivered to the Japanese air force. The watch is known as the Tensoku-Dokei, or celestial watch. Today, pilot watches have a strong masculine look that fits easily into the modern aesthetic. The present watch is a fine example and makes an excellent addition to a collection focused on design, modernity and technical ingenuity.