I have the Littman Master Cardiology. I am a physician. This is my third or fourth stethoscope in more than 20 years of practice. I had the Cardiology II for many years and thought it was great. Then someone gave me a Sprague-Rappoport 3-head Proctor-Harvey model, which had excellent acoustics but the tubing was very sensitive to interference from external touch. Also, it wore out pretty fast -- sensitive to heat and cold, I think.(a quick online just now suggests that Welch Allen now makes these and may have better tubing, more like the Littman). I have had the Master for a few years and like it very much. I would only have a black stethoscope, as I am a traditional kind of guy.