The Littmann Classic III is the most popular stethoscope purchased by nursing students. It includes one piece diaphragms for better sound quality on adult and pediatric patients. The pediatric side can be converted to a traditional bell for adult low frequency sounds. The Cardiology IV has two tube in one design to provide better acoustics for listening to heart and lung sounds. This would be an excellent upgrade for a Nurse Practitioner. The Prestige Clinical I and Cardiology are economy versions of the Classic III and Cardiology IV, respectively. They provide similar acoustic ability at an economical price.