The 631L is designed for close talking, handheld applications in quality sound installations where background noise is a problem. The frequency response, especially tailored for voice communications, provides a crisp, clear, highly intelligible sound with 360 degrees minimization of background noise. A soft lip guard is positioned to assure proper close talk voice spacing by the operator. The dynamic cartridge has a rugged polyester diaphragm which resists moisture, temperature extremes, most acids, alkalines and solvents. Molded in high impact Cycolac, the 631L comes with a permanently attached, heavy duty, four conductor, two shielded coil cord. The low impedance 631L has a DPDT long life, trouble-free switch and is factory wired normally open.