The CR577 features a ulta-clear ceramic microphone cartridge,
low-noise audio amplifier with volume control and a variable tone
control to "dial in" your audio.

 

• 1 Inch Diameter Ceramic Microphone Cartridge
• Low-Noise Audio Amplifier IC
• External Volume (Gain) Control on Back Panel
• External Tone Control on Back Panel
• The Highest Quality, Soft-Shell Neoprene Microphone Cord
• Seperate Battery Cover for Quick and Easy Access
• Metal Front Grill
• Wired for 4-Pin Radios
  
  Wiring Information for different radios included. (Wire Color and
  corresponding function)