3M Littmann Cardiology IV Black 27 Stethoscope Wheelchairs Accessories 75 D * Electrical Requirements: 416700 75 D * Electrical Requirements: 110V 220V (50 60Hz) * Power Rating: 13 W * Operating Temperature: 20¯ 100¯ * Operating Relative Humidity: 0 93% non condensing * Storage & Transport Temp: 0¯ 120¯F * Air Discharge: Full automatic rapid exhaust mode Outstanding acoustics with better audibility of high frequency sounds (adult side firm pressure) * Tunable diaphragm: Hear high or low frequency sounds by slightly adjusting pressure on the chestpiece * Standard Finish Chestpiece Black Tube Stainless Stem and Headset * Dual lumen tubing: Two sound paths in one tube eliminates the rubbing noise of traditional double tubes * Next generation tubing lasts longer and resists stains * Not made with natural rubber latex or phthalate plasticizers * Headset is easily adjusted for individual fit and comfort * Angled eartubes align with ear canals * Seven year warranty provides greater peace of mind