This 3M™ Littmann® Electronic Stethoscope Model 3100 is a very comfortable and featherweight , sleek and classic device that provides Ambient Noise Reduction technology in the surroundings and sound strengthening to generate confidence in hearing. The stethoscope has an advanced sound sensor which provides the best sound experience through this cardiology stethoscope. 85 percent of the surroundings noise is reduced by the use of Ambient Noise Reduction technology. The doctors can concentrate on what they want to hear with the Frictional noise reduction technology. The sound amplification can go up to 24X.