This is a 4-pin microphone voice sound sensor module based around the LM393 chip. It features an electric condenser microphone, single channel signal output with a low level output signal used for sound control light. Features & Specs * Working Voltage DC: 4-6V * Comparator Circuit: LM393 * Power on LED Light: LED1 * Power Supply Voltage: 3-24V * Hole Inner Diameter: Approx. 3mm * Board Weight: 5g