Shimpo Instruments DT-900-PR TechStrobe Stroboscope Professional Kit includes a Phase shift feature which allows the TechStrobe operator to advance or retard the flash timing by degrees of angle, without changing the actual flash rate (FPM) of the TechStrobe. Shimpo DT-900-PR TechStrobe Stroboscope features rotary and push button controls for internal flash (FPM/RPM) control, external triggering, tachometer mode and Phase shift control. Made in Japan.