Rales, rhonchi, stridor, and wheezing are all sounds heard when using a stethoscope. Without this unique piece of medical equipment, serious health conditions could go unnoticed and undiagnosed. Diseases such as heart failure, pneumonia, and emphysema are just a few serious conditions first detected with this basic medical device. A stethoscope is also beneficial for monitoring blood pressure, which also helps with early diagnosis of heart conditions. Pediatric stethoscopes utilize special designs to listen to the lungs and hearts of children. A variety of different stethoscopes are available in new or used condition from the reliable sellers on eBay. For example, Littmann produces many different models of Littmann stethoscopes, some of which are specific to medical specialties like cardiology. If you work as a medical professional, make sure you have the right equipment to make those important diagnoses. Someone's life may depend on it.