This is a massive (47mm.) extremely rare all original 1960 Longines Aviator Israeli Air Force rare steel single-button fly-back aviators chronograph having an original dial and handset with rotating steel bezel and original large onion crown. The manual winding Caliber 12.68Z. LONGINES movement was just meticulously cleaned and is accurate, with the flyback chronograph function working properly. This watch is accompanied by an extract from the LONGINES archives describing this exact piece. This is a military issued watch for Israeli Air Force-extremely rare, and like most LONGINES watches… undervalued…in my opinion. This watch displays excellent overall condition and is without any flaws worth mentioning. This is a true investment watch. There are many Rolex Submariners out there at this price…but hardly any of these rarities exist.