Perform tachometer RPM measurement, stroboscopic speed and motion analysis with the Extech 461825 Combination Photo Tachometer and Stroboscope. The unique display reverses character direction depending on which measurement mode you are using. The tachometer memory stores last, max, and min readings for recall. The strobe features course and fine flash rate adjustments in 3 ranges. It is complete with 4 AA batteries, reflective tape, and carrying case.