When components of an automobile engine are not functioning properly, they usually sound a warning in the form of noises not common to normal operations. Fortunately most noises possess characteristic! of their own which help to identify the sources, coupled some knowledge of their meaning.
Today profession! 560 'mechanic likes more to use a stethoscope which accurate and flexible in use.
It is similar to one used by doctor and may be used even while driving the car.
The unit Is consisting of earphone, amplifier, switch, dry cells 561 and carbon microphone, Furnished with instructions, and a chart of possible different noise, probable source, mike position and how check.