With an external antenna,supports Bluetooth 2.1 + .Enjoys Bluetooth connections up to 10m.Makes the transmission effortlessly,Provides 2 sets of stereo channel outputs to improve the sound quality and reduce the background noise,with a wide dynamic range without boom Available IR remote control to adjust the volume,sound selection,station and other functions.No need to walk in front of the amplifier to debug,very convenient As long as your music or files are located in your storage device,the amplifier read the MP3 files directly, input function makes it compatible with the phone,DVD,CD,MP3,other audio applications,gives you high-quality music enjoyment Built-in FM function,beguiles your boring time by listening to the news.With loudspeaker protection,when the amplifier is turned on to speakers from high volume bursts of audio Colour:Black Material:aluminum alloy Size:16.8x11.5x 5.4cm Output power:20W Frequency response:20Hz - 20KHz SNR:85dB FM frequency:87.5 - 108MHz Input power:DC 12V/5A Remote controller battery:3V CR2025 lithium metal battery (included) Package Contents: 2 x Bluetooth Amplifier 2 x Remote Controller 2 x English User Manual Only 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.