The 3M Littmann Cardiology III Stethoscope combines outstanding acoustic performance with exceptional versatility. Its innovative design offers a patented tunable diaphragm on each side of the chestpiece. BenefitsDouble-sided chestpiece, for adult and pediatric auscultationPediatric side can be converted to an open bell for low frequencies using non-chill bell sleeve (included).Pressure-based sound frequency adjustment with tunable diaphragmParallel noise-reducing sound channels in the tubes