Littmann 2138 Classic II SE (Teaching)
Black and burgundy tube colors allow instructor and student to easily differentiate headsets. Longer, 40-inch (102cm) tube for easier movement around the patient. Versatile chestpiece design provides high acoustic sensitivity with both a tunable diaphragm and open bell.
Tunable diaphragm: Hear high or low frequency sounds by slightly adjusting pressure on the chestpiece.