Speed adjustment of this xenon flashlamp stroboscope is a snap due to its instantly-responding LED display. The main speed and vernier (fine-adjustment) allows you to fine-tune your flash rate to .1/second! (±.08 flashes/second). The output is adjustable from 3.0 to 83.3 flashes per second. The sturdy 20 cm3 steel box has large urethane bumpers to keep it from moving during use. The carrying handle on the top of the unit makes it easy to move from class to class. Operates on 115 V/60 Hz grounded and comes with operating directions.