Descriptions: 1.Signal output indication. 2.Single channel signal output. 3.Circuit board output switch quantity. 4.The output effective signal is low level. 5.Can detect the intensity of the sound environment. 6.With the retaining bolt hole, convenient installation. 7.When there is sound, outputs low level and the signal light. 8.Can be used for Acoustic control light, give sound and light alarm working with Photosensitive sensor ,and sound control,sound detect Note: This sensor only recognizes the availability of sound (vibration principle) can not identify the size of the sound or the specific frequencies of sound.