Echo adjustment in the front, Volume and Talkback controls in the Back (inside)

Sensitivity: -42 dB at 1,000 Hz
Impedance: 3 K ohm and less at 100 Hz
Frequency Response: 150-3,500 Hz
Echo Frequency Response: 200-3,000 Hz
Battery: DC 9V
Mic element: Omni Directional electret condenser type.
Front Slide control Controls the amount of echo.
Dual Inside controls control the gain and echo speed.