One-inch traditional bell (pediatric) and 3/4 inch bell (infant) combined with a patented floating diaphragm * Stainless steel chestpiece * Excellent acoustic seal and comfortable fit with patented 3M⁄ Littmann Snap Tight soft-sealing eartips * Comfortably angled anatomically correct headset * Single-lumen tubing is available in attractive colors * Three-year warranty