The Diaphragm (Flat Side): Best for capturing high-frequency sounds, such as normal lung respiration, bowel movements, and standard heart beats.
The Bell (Cup Side): Engineered to isolate subtle, low-frequency sounds, including cardiac murmurs, bruits, and deep vascular anomalies.
The Rotating Stem: A built-in acoustic valve indexes sound to only one side at a time, sealing off the opposite side to block out ambient room noise.