The NS-600 LED stroboscope is designed to measure the speed of a rotating object or one that is cycling in a linear repetitive pattern ..... without contact or reflective tape. When the flash rate and rpm rate are identical, the target will appear frozen" visually. If the flash rate is adjusted slightly, the target would be put into slow motion for detailed motion analysis, observation or trouble-shooting.The NS-600 features a rugged cast-Aluminum housing, the latest LED technology and compact size making it a perfect choice for use anywhere on the factory floor. The NS-600 is ideal for speed, motion and vibration analysis, such as rotating shafts, fans, cams, etc.NS-600 automatically adjusts flash duration for ultra high speed and features a user-selectable flash duration for those applications where the user wants to optimize either the image "sharpness" or increase the "brightness" to the highest levels.