The Robinair LD7 Premium Refrigerant Leak Detector features a new color graphic display that highlights leak sizes in two unique ways. Bar graph mode shows the amount of refrigerant detected in the air and changes colors as the sensor gets closer to the leak. Sweep mode allows the user to see the level of refrigerant detected in the air through a line graph that helps the user trace back and forth to pinpoint the exact source of the leak. The LD7 also uses an audible alarm to alert technicians of a refrigerant leak, UV LED lights to locate leaks using UV dye and an inspection light for searching in dark locations. The LD7 is compatible with most commonly used refrigerants today, including R-134a and 1234yf, and is equipped with a stable, long life sensor that will last up to 10 years. The LD7 meets all of the current industry leak detector standards and is covered by a 2-year warranty. Uses 4 AA batteries, included.