3M Littmann Cardiology IV Diagnostic Stethoscope, 6152, Standard-Finish Chestpiece, Black Tube3M Littmann Cardiology IV Diagnostic Stethoscope: Excellent acoustics that can hear high frequency sounds clearly (adult side) Tunable dial: You can hear high or low frequency sounds simply by adjusting the pressure on your chest. Dual lumen tubing Two sound paths in one tube reduce rubbing noises from double tubes Details Excellent acoustics that can hear high frequency sounds clearly (adult side) Tunable dial: You can hear high or low frequency