Power supply: external power supply Input voltage: 12V Channel: four in and one out Sensitivity: 110dB Frequency response: 20Hz-20KHZ Frequency conversion mode: analog audio The principle of howling: The microphone repeatedly picks up the sound reproduced by the speaker to form positive feedback. When the volume exceeds a certain limit, this same frequency signal cause the amplifier circuit to feedback and then howl be generated Causes of howling: The incident angle of the microphone is close to the radiation angle of the speaker, or the distance between the microphone and the speaker is too close, or the frequency response characteristics of the venue are not good How to howling: Automatically track the feedback point frequency, automatically adjust the Q value bandwidth, automatically the sound feedback and maximize the protection of the sound quality (Slight color difference is subject to the actual product, which does not affect the use) Plug Type:EU Plug,it applies to Indonesia, Germany, France, Spain, Italy and so on Voltage:AC100-240V Color: Grey Material: Metal Package Contents: 1 * Microphone Feedback Suppressor Only the above package content, other products are not included. Note: Light reflection and different displays may cause the color of the item in the picture a little different from the real thing. The measurement allowed error is +/- 1-3cm.