Seiko Sliding Rule chronograph Pilots SND255P1 WatchSeiko Flightmaster Pilot Slide Rule Chronograph SND255 SND255P1 SND255P Men's Watch A sophisticated piece of scientific art to mark unusual and ambitious achievements while in air. The highlight of the high end Seiko Prospex Flightmaster is its shining, deep blue, bidirectional timing compass bezel and dial. This is a rare bird even in the Seiko chronograph range for its rotary slide rule that makes rapid calculations and conversions possible for a