Working Voltage:DC 3V-5V The SSM2167 is a low-voltage,low-noise mono microphone preamplifier,for ideal for low-power audio signal chains.This preamplifier includes a built-in compression and noise gate,For this function,it is better than just using an op amp in the preamplifier circuit.The dynamic range of the compressed microphone signal reduces the for peak signal level and adds additional gain to the low level signal.The noise gate attenuates the signal level below a certain threshold,in order to amplify only the desired signal,such as speech, and reduce the noise in the output signal.These features will help improve the clarity of the voice signal received by the microphone. Size:2.2x1.5cm/0.87x0.59inch Note: Please allow 1-3mm error due to manual measurement. pls make sure you do not mind before you bid Due to the difference between different monitors, the picture may not reflect the actual color of the item. Thank you! Package Includes: 1x SSM2167 Microphone Preamplifier Board