The Littmann® Select Stethoscope features a patented tunable diaphragm that alternates between bell and diaphragm modes with a simple pressure change on the chestpiece. Its reliable and clear acoustics offer an advantage to health care professionals when listening to heart, lung and blood pressure sounds. Also features single-lumen tubing and comfortably angled anatomically correct headset. Has a coated alloy chestpiece. 2 year warranty.