This exclusive design features an improved valve mechanism that virtually eliminates acoustic leakage and a chestpiece key to facilitate after market service. Features: Threaded chestpiece drum of chrome plated zinc permits the use of five interchangeable chestpiece fittings - an adult and pediatric diaphragm, and three bells (11/4", 1", 3/4") - for complete diagnostic capability in most patients Latex-free, double tube configuration Proprietary valve mechanism eliminates acoustic leakage Adjustable chrome-plated brass binaurals Complete with an accessory pouch containing the bell chestpieces, chestpiece key, 2 spare diaphragms, one pair of mushroom eartips, and one pair of silicon eartips Inspected and packaged in the U.S.A