Seiko Chronograph Sliding Rule Pilots Flightmaster Mens Watch SND253P1Seiko Flightmaster Pilot Slide Rule Chronograph SND253 SND253P1 SND253P Men's Watch A sophisticated beauty with soft responsiveness and always a positive feedback, the Seiko Flightmasteris for high end aviation and the bi directional timing and compass bezel comes very rarely in chronograph models. Theres also a rotary type, slide rule function to convert units and calculate fast the essential flight data. But then again, computing speed or fuel