A stethoscope is a medical device that is used to listen to heart, lung, and other body sounds. It is an important tool for doctors, nurses, and other medical professionals. The stethoscope is made up of three parts: the diaphragm, the bell, and the tubing. The diaphragm is a thin, round piece of plastic that is placed against the skin. The bell is a small, cup-shaped piece of metal that is placed over the diaphragm. The tubing connects the diaphragm and the bell to the earpieces.