Fortis Watch Aviatis Aeromaster Steel Chronograph 656.10.10 L.08. For pilots who spend their lives above the clouds, items necessary for a hard days flying must be simple and purposeful. Good readability, robustness, anti reflective glass and a glare free case are the most important performance characteristics. Just like the original Fortis B 42 model, the 656.10.10 Fortis Aeromaster Steel Chronograph takes up the reins of these properties and perfects them, right down to the smallest detail.