Description: DC 5V power supply, mounting screw hole is 3mm. For sound detection module has two outputs: AO, analog output, real-time output voltage signal of the microphone; DO, digital output, when the sound intensity reaches a certain threshold, the output high and low signal. There are threshold level output flip. High sensitive microphone and high sensitivity. Has power indicator light; the comparator output has indicator light. Specification: Size: 4.5 x 1.5cm Color: Red Package Includes: 3 Pieces Sound Microphone Sensor Note: Color maybe slightly different due to different monitor. The above size is measured by hand, please allow slightly difference. Thanks !