Two-sided chest piece with tunable diaphragms on both the adult and pediatric sides. Single-piece tunable diaphragm is easy to attach, and easier to clean because its surface is smooth without crevices. Pediatric side converts to a traditional open bell by replacing the single-piece diaphragm with a non-chill rim. Next-generation tubing provides longer life due to improved resistance to skin oils and alcohol, less likely to pick up stains. Small tunable diaphragm is useful for pediatric, small, or thin patients, around bandages, and for carotid assessment.