Longines L3.721.4.53.6 Spirt Pilot Flyback, LONGINES SPIRIT PILOT FLYBACK, L3.721.4.53.6, manual winding watch, Ø 39.50 mm, stainless steel and ceramic bezel., Chronograph flyback, mechanical movement with manual winding beating at 28800 vibrations per hour, with a power reserve of approximately 68 hours., Bi-directional rotating bezel, water-resistant to 10 bar, scratch-resistant sapphire crystal, with several layers of anti-reflective coating on both sides., Black matt dial, swiss super-luminova®., Stainless steel bracelet, with double security folding clasp with micro adjustment system., LONGINES SPIRIT PILOT FLYBACK, The LONGINES Spirit Pilot Flyback collection captures the brand’s persistent drive for innovation. This chronograph, with its flyback function, highlights LONGINES’ pioneering expertise in this field. The winged hourglass brand introduced its first flyback-equipped model in the early 1930s and secured a patent for the technology on June 16, 1936, marking a world-first achievement. Designed as a groundbreaking tool for pilots, the flyback complication makes it possible to time successive flight stages, greatly enhancing navigational efficiency. The precision of the LONGINES Spirit Pilot Flyback is powered by an exclusive LONGINES calibre, fitted with a silicon balance spring and resistant to magnetic fields. This hand-wound mechanical movement is officially certified as a chronometer by the COSC.