The Littmann Cardiology IV stethoscope offers: Better audibility of high-frequency sounds. Tunable diaphragms on both the adult and pediatric sides of the chestpiece. Single-piece diaphragm that’s easy to attach and easy to clean because the surface is smooth without crevices. Pediatric side of the chestpiece converts to a traditional open bell by replacing the single-piece diaphragm with a non-chill rim. Dual-lumen tubing eliminates the rubbing noise of traditional double tubes. Next-generation tubing is not made with natural rubber latex or phthalate plasticizers. Improved resistance to skin oils and alcohol for longer tubing life and less likely to pick up stains. 7 year Warranty