Accutrak VPE Professional Kit Ultrasonic Leak Detector Easily detects any gas that generates ultrasonic sound during flow, including vacuum leaks Capable of detecting leaks equivalent to 1.5 oz/year of refrigerant Visual output - 10 element bar graph Audio output - 0 Hz to 4 kHz natural sound conversionThe AccuTrak VPE Professional Kit is designed for technicians who work in noisy places, or who regularly need to find smaller leaks. The VPE Professional Kit includes all the great features of our VPE Standard Kit upgraded with professional Noise Cancelling Headphones, a convenient Belt Pack, and a larger case to keep everything together. These high-quality headphones eliminate all background noise, allowing a technician to effectively find the smallest leaks - even in very loud environments.