The stethoscope is used for auscultation, or listening to sounds produced by the body. It is used primarily to listen to the lungs, heart, and intestinal tract. It is also used to listen to blood flow in peripheral vessels and the heart sounds of developing fetuses in pregnant women. Machined stainless steel chest piece. Double sided chest piece technology. Diaphragm diameter 15 cm diaphragm diameter 3 cm (1.25 inch approx) reliable & high acoustic sensitivity offer an advantage to health care professionals when listening to heart, lung and blood pressure sounds.