Feature:- Portable HIFI Digital Bluetooth and AUX Audio Power Amplifier.- Support TF Card, U-Disk, AUX, MP3 play and BT Connection.- With Treble, Bass, and Volume control, Very easy to use.- Low distortion supplies clearer, stronger and more powerful sound.- With Remote control, Easy to adjust volume. Channel 2.0 output.- Support DC/AC power in, Suitable for Home and Car.- Support FM Radio (But not professional, pls understand).Specification:Type: Digital HIFI Power AmplifierSupport: Bluetooth/SD/TF/USB/AUX/RCA InputFunction: Power AMP/Music Player/FM RadioAUX Input: 3.5mm Audio at frontRCA Input: PC /MP3 /DVD /CD etc at rearAudio output: L/R 2.0 ChannelBluetooth Version: 5.0USB Version: 2.0Output Parameter:Max Power: 45W+45W (RMS)Rated Power: 15W+15WRated Impedance: 4-8Distortion: 0.02%S/N Rate: 92dbPower Supply: DC 12V (>=3A) / AC 110V/220VRemote Power: 1x CR2025 Battery(Not Included !)How to match the AMP and Speaker:1. The impedance of the amplifier is the same as the speaker, can not be too far apart.2. The power of the amplifier is 1.5 times than speaker to obtain a enough sense of strength.=> If the output impedance of the amplifier requires 4-8, the impedance of your speaker should also be 4~8, the sound of 4 ohms is louder, and the 8 ohms is smaller;=> If the output power of the amplifier is 35W, the speaker should be around 20W. For the 1.0 channel, the speaker power is 20-30W, for the 2.0 channel, it is 2x(20-30)W.=> If the amplifier is full frequency, the wider the frequency response of the speaker, the better, such as 100~18KHZ.TIPS: The speakers must be based on impedance and power, regardless of dimensions. If the sound is intermittent or hoarse during increasing the volume, it means the speaker and amplifier are not matched, Pls use small sound or change a suitable speaker. Pls make sure that the required power supply is used and working properly.NOTE:1. If you want to use the DC Power, Pls buy the power adapter by yourself.2. Do not create a folder in the U-disk or TF-card, but directly put the MP3 file in it.Package Included:1 x Audio Amplifier1 x Remote (Battery NOT included!)