This is a noise cancelling dynamic CB microphone with a flexible black cord so you can easily and comfortably communicate. 2 position momentary slide switch with normally open contacts makes it simple to use. Frequency Response 100Hz-8kHz. Output Level at 1kHz Open Circuit -72dB (ret. 0dB equals1V Ohm Bar). Power Level -55dB (ret 0dB equals 1Mw 10 Ohm Bar). Output Impedance 2000 Ohms (Matches 600-5000 Ohm Inputs). The professional driver's choice for over 50 years RoadKing mobile communication devices and accessories keep you clearly connected. The combination of professional-grade durability convenient capabilities and reliable technologies have set the professional driver standard for over fifty years. With superior noise-canceling technology and rugged design RoadKing quickly became the popular CB microphone choice among professional drivers. We understand the unique needs of todays professional drivers and what they look for in mobile communications. The CB radio is an essential element for communication and safety while on-the-go. RoadKing is your trusted source for reliable affordable CB communication equipment. The RoadKing RK56B has a 4-pin connector and features a black Cycolac case for exceptional impact-resistance.