Constructed from premium-grade stainless steel, the MDF® Stainless Steel Dual Head Stethoscope is one of the most widely sought after professional diagnostic scopes today. MDF777 provides accurate auscultation of heart, lung and blood pressure sounds as well as overall durability and aesthetics. Chestpiece: The deluxe adult stainless steel Dual-Head Chestpiece and full-rotation Acoustic Valve Stem are precisely machined for the highest performance and durability. The Diaphragm is fitted with ultra-sensitive Diaphragm sealed by the non-chill Diaphragm Retaining Ring to provide a secure acoustic transmission. The extra large Bell crowned with a non-chill Bell Ring provides greater acoustical amplification, isolation of low frequency sounds and offers patient's comfort. ErgonoMax™ Headset: Machined and polished stainless steel tubes, enclosed internal spring and MDF ComfortSeal™ Eartips are designed for long lasting comfort and high performance acoustic transmission. Acoustic Tubing: Heavy-walled and internal acoustic pathway in the Y-configuration, the tubing is designed to maintain acoustic integrity. Acoustic Tubes are constructed of non-cracking, non-sticking high-density latex-free PVC. Accessories: Additional (2) ComfortSeal™ Eartips, (1) ultra-sensitive Diaphragm and (1) ID tag.