We made it Scream"N to give you the advantage when working in noisy work areas. The PPCT volume is adjustable so you can make it scream, or adjust it for quieter work environments. The PPCT emits two distinct tones enabling you to differentiate between circuits above 10 ohms or below 10 ohms. The PPCT also emits a warble tone when it detects voltage.The 10 foot green lead keeps everything within reach. And should you find the need for a longer lead we have included a 10 foot extension lead. The PPCT is powered by two AA batteries which makes a portable stand alone tester. The automatic shut-off will maximize battery life..