Use of TDA7388 digital amplifier chip as the core.Neat outlook and firm welding points.High and good performance, low noise and distortion.REM terminal: high level is effective, please connect the REM terminal for car use. For general application or DIY use, please directly connect the positive pole of supply, otherwise there will be no sound Line inputs 1 and 2 are , suitable for four-channel mode, each channel works independently; All switches are in the ON position, it is the 2-channel input 4-channel output mode; The two left and right channels output the same sound, equivalent to widening the stereo mode of the sound field.Compatible Audio & Video Equipment Style: AmplifierChip type: TDA7388 x 1Input voltage: DC 12-18vOutput : 4x41W, 4ohm Max.Channel: four channel surround soundOutput impedance: 4-8ohmFrequency response: 20hz-20khzSpeaker Recommendation: each channel 3-6.5 inch; 4-8ohm; within 50Wcolour:RedMaterial:Plastic + Metalsize:76 x 58mmPackage Contents:1 x amplifier boardOnly the above package content, other products are not included.Note: Light 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.