Handcrafted Since 1971 | Lifetime Warranty | Free-Parts-for-Life Program | Latex Free. The MDF MD One Stethoscope delivers accurate auscultation of heart, lung, and Korotkoff sounds with acoustic integrity and clarity. Chestpiece: Handcrafted stainless steel dual-head. The full-rotation acoustic valve stem with green indicator dot to easily identify the active sound channel and seals in sound. The chestpiece is fitted with a diaphragm and a non-chill retaining ring. Tubing: Constructed of thicker, denser, latex-free PVC. Patented Acoustic Pyramid Chamber: Made of metal-alloy located in the acoustic tubing below the spring keeps the tubing channel open for maximum sound transmission into the headset. ErgonoMax Headset: Hand polished, pre-angled stainless steel headset features a patented internal dual-leaf spring construction for durability and custom fit. Patented SafetyLock eartip adaptors. Included Accessories: 2 extra sets ComfortSeal eartips, diaphragm, and ID tag.