AutoStrobe 490ST with Stretch TuningThe Model 490-ST includes stretch tuning capabilities for enhanced tuning of string or percussion instruments, such as the piano, bass, guitar, marimba, steel pan, and others.Only Peterson strobe tuners respond at the speed of light to display relative tuning of any audio source to 0.1 of a cent (1/1000 of a semitone) accuracy! With such new AutoStrobe models as the Model 490, students, technicians, and musicia...