Product information: 3M Littmann Master Cardiology Stethoscope, Plum Tube, 27 inch, 2167: Master Cardiology Stethoscope is characterized by the best acoustic response of all Littmann mechanical stethoscopes Tunable diaphragm and pediatric adapter Dual-lumen tubing offers superior sound quality. Salient features of 3M Littmann Master Cardiology Stethoscope, Plum Tube, 27 inch, 2167: - Tunable diaphragm allows the user to conveniently alternate between the low- and high-frequency sounds without turning over the chestpiece - Handcrafted solid stainless steel chestpiece - Dual-lumen design eliminates tube noise artifact from two tubes rubbing together - Portable convenience of a single-sided chestpiece - Excellent acoustic seal and comfortable fit with patented 3M Littmann Snap Tight Soft-Sealing Eartips - Comfortably angled, anatomically correct headset - Patient-friendly, nonchill rim and diaphragm. Special procedures adaptor for difficult site or pediatric auscultation