Steelman EngineEAR Noise and Vibration Detection System saves time when trouble-shooting, pinpointing noises and locations of worn bearings & bushings, noisy valves & lifters, broken or worn gear teeth, faulty fuel injectors, wind or air leaks, and annoying squeaks and rattles. The included headphones amplify sound while shutting out surrounding noise, and a flexible shaft is also included to reach the tightest areas. The included microphone is also non-conductive so that it will not zap expensive computer circuitry.