– FS2004/FSX Davtron Chronometers M550 flight2000it 15 years ago FS2004/FSX Davtron Chronometers M550. New stand alone XML gauges with four functions available (GMT, LT, FT and chrono). By Pierre Fasseaux. 570 Kb – FS2004/FSX Davtron Chronometers M550– FS2004/FSX Davtron Chrono M550 M877 Upgrade– FS2004/FSX Davtron Chrono M550 M877 Upgrade