Type: Noise Cancelling Frequency Response: 40Hz-20KHz Input Impedance: 60 ohms Sensitivity: 102 dB/mW Cord Length: 8 feet Features: The Koss Race Tracker stereophone is an extra-durable stereophone that delivers amazing passive noise reduction. Like the QZ99, the Race Tracker was initially designed for use with racing radio scanners and metal detectors users, and provided a behind-the-head headband design. Since then, the Race Tracker has become a favorite for a wide range of listeners who need to cut high levels of ambient noise and do not want the constraints of a conventional headband. Built to withstand the rigors of outdoor or indoor use, the Race Tracker features both a 3.5 mm and 6.4 mm plug and will connect to most radios and scanners. The Race Tracker features neodymium magnet structures for outstandi...