The original Rappaport Sprague stethoscope was arguably the best acoustic stethoscope ever produced, equaling or surpassing today's top of the line models . Most copies are just plain junk, but this version is VERY close to the original. Some criticize the Rappaport Sprague, claiming noise artifact from the two tubes rubbing. This really isn't a problem unless you are actually walking while using the scope. It's not only a great scope, it's an iconic piece of medical history.