With ADC’s Adscope 658 Electronic stethoscope, you’ll hear sounds you may have missed with a traditional acoustic instrument. The contact-activated microphone filters higher-frequency background noises that typically interfere with auscultation, then amplifies heart and lung sounds up to 18X. Includes noise-filtering contact microphone eliminates background interference. Eight-step volume control with last-setting memory. Cardiology headset with bilumen tubing and stainless-steel binaurals. Multifunction button controls the frequency mode (bell or diaphragm) and the volume (eight levels). Backlit LCD display powers down automatically if not in use. Rechargeable Li-ion battery, twenty hours of continuous use on a full charge. High-impact thermoplastic housing withstands drops, bumps, and other contact. Measures 30 inches and weighs 175 grams. Contact microphone measures 7 mm in diameter, suitable for use on any size patient.