Amazon.com: Durabasics Classic 3, Cardiology 3 & Cardiology 4 Stethoscope Accessories Kit for Littman Stethoscope Replacement Parts & Littmann Stethoscope Parts - Fits Classic III, Cardiology III & IV - Black : Industrial & Scientific
Amazon.com: Replacement Tube by Reliance Medical fits Littmann® Cardiology III® 3 Stethoscope (Black) : Industrial & Scientific