ADVANTAGE: Digital amplifier has a higher overload capacity than analog amplifier, and it won't cause crossover distortion, transient inter modulation distortion and you don't have to worry about the loudspeaker internal resistance.     SUPPORTS MANY AUDIO INPUT WAYS: It supports many audio input ways including Bluetooth, USB, TF card and audio input jack.     INSTRUCTIONS: Dual channel of 50W+50W power output, 100W subwoofer output and a wide input voltage range from 12V to 26V DC.     SOUND QUALITY IS VERY GOOD : Sound quality is very good by using this audio power amplifier module.     APPLICABLE SPEAKER IMPEDANCE: Applicable speaker impedance are 4/6/8 ohm, great for turning normal speaker into Bluetooth speaker.          Chip:TPA3116     Audio input:Bluetooth, USB, TF, audio input jack     Audio format:MP3, WMA, WAV, FLAC     Appropriate impedance:haut-parleur 4, 6, 8 ohms     Appropriate impedance:speaker 4, 6, 8 ohms     Input voltage:12 ~ 26V DC     Colour: picture color     Material: ABS     Size: 12.4x8cm          Package Contents:     1 * Power Amplifier Board          Only the above package content, other products are not included.     Note: Light shooting 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.