Features: Hold button freezes display to capture transients or for hard-to-read locations, Battery SavR™ turns instrument off when not in use, Pocket-sized convenience Easy to Use: Only four easy steps alert you to static charges before they cause harm: Press PWR ON/HOLD button once. Discharge your body by touching a grounded metal object. Point the aperture toward a grounded surface and press the ZERO button twice. Aim the instrument toward the target surface at a distance of 1 inch. Read voltage and polarity of the charged surface on the display.