3M Littmann Cardiology S.T.C. (Soft-Touch Chestpiece) Stethoscope, Black Tube, 27 inch, 4471 Precision, balanced, ergonomically designed chestpiece moves easily between various auscultation sites and delivers high acoustic performance Soft-Touch insert provides comfortable, secure grip in at least three hand positions with and without gloves Tunable diaphragm responds with a simple pressure change to capture low and high-frequency sounds Two-in-one tube design (dual lumen) eliminates noise interference from two external tubes rubbing together Anatomically correct and angled headset channels sound into the ear canal