The T3 Innovation AC120 Arc Chaser is a serious piece of technology. This unit is equipped with Spread Spectrum Time Domain Reflectometry (SSTDR) which gives the AC120 an accuracy within 1% to a fault. The T3 AC120 Arc Chaser monitors intermittent opens, shorts and faults and can work on both energized and unenergized cables. Keeping up with the rest of the T3 line of products, the display is crystal clear with beautiful color graphics.