The flashes enable high-accuracy rotational speed measurement and stop motion analysis. The device provides a wide measuring range from 40.0 to 35,000 rpm. With a phase adjustment function, it is possible to move an image while maintaining synchronization. Provided with an external signal connector as a standard feature, synchronization and delayed flash using external signals are also possible. A xenon lamp is used as the light source. Power is provided by a dedicated rechargeable NiCd battery.