The left-handed tachometer H 51345 is a mechanical speed-measuring device designed to monitor engine rotational speed in Sulzer ASL25 installations with left-hand rotation. Built for accuracy and reliability in harsh operating environments, this tachometer provides clear, consistent RPM readings essential for engine control, diagnostics, and safe operation. Its robust construction and precise internal gearing ensure stable performance under vibration and temperature variation, making it a dependable instrument for long-term monitoring in marine and industrial engine rooms.