The Tracerline Marksman ultrasonic diagnostic tool converts inaudible sound into audible, natural sound, allowing technicians to hear such problems as vehicle component leaks and wear. The TP-9370 Marksman Master Kit comes with a receiver, headphones, two anodized probes and an ultrasonic emitter. When attached to the receiver, the 12-inch hollow probe accentuates air sounds, while the solid contact probe accentuates sounds of wear or grinding.