3M Littmann Classic II Paediatric Stethoscope Black 2113 Features a two-sided chest piece offering high acoustic sensitivity for superior performance and is designed with traditional bell and diaphragm chestpieces sized and acoustically precise for children and infants, with a solid stainless steel chestpiece that includes a one-inch traditional pediatric bell or a 3/4-inch infant bell combined with a patented floating diaphragm.