littmann stethoscope, The sprague rappaport type stethoscope. littmann stethoscope, The sprague rappaport type stethoscope1. Zinc alloy chestpiece, excellent sound conduction, little acoustic attenuation.2. Standard dual PVC tubing, well-sealed dual sound condution channel, good resistance to ambient interference, color is optional.3. High quality rolled stell connecting spring, tighjtness is ...