The PST30 Stroboscope Tachometer by PYLE is built for maximum performance, portability and ease of use. The PST30 is a hand-held battery powered LED Digital Stroboscope for use in speed measurement as well as motion analysis. It is fitted with 18 state of the art, super-bright LEDs. The strobe rate can quickly be set anywhere within the full range while making fine adjustments is just as easy. With the PST30 you can analyze speed, motion and vibration on rotating shafts, fans or perform hi-speed motion analysis on speakers, ink-jet printing and more. Power is supplied by 4 x AA batteries (not included)