3M™ Littmann® Electronic Stethoscope Model 4100WS with Ambient Noise Reduction
 
 
3M
The Littmann Electronic Stethoscope Model 4100WS features amplification and proprietary Ambient Noise Reduction (ANR) technology allowing you to reduce ambient noise by an average of 75 (-12dB) without eliminating critical body sounds. Three frequency modes are available for listening to heart, lung, and other body sounds: Bell (20-200 Hz), Diaphragm (100-500 Hz), and Extended Range (20-1000 Hz).