ADJUSTABLE TREBLE BASS EQ: Bass signal output can operate independently and the bass amplitude range is fine-tuning. The subwoofer output is controlled separately. Maybe appropriate to adjust the style effect according to your needs for sound effect. WIRELESS BLUETOOTH CONNECT: Built-in 2.1 version and that ranges up to 50' + feet and has thermal power protection circuitry and variety spring loaded speaker terminal. Also, installed with HD sound and LED digital screen that your stereo is working. BRIDGEABLE AMPLIFIER: This latest 2 channel subwoofer amplifier with 200 watt RMS at 4 ohm impedance and a frequency range between 10-40kHz for unrivaled sound superiority. Fully marine grade rating at IP-41, a class D circuit, and RCA audio connector. AUXILIARY INPUT: Save MP3 audio files to a memory card and playback through the USB or SD card reader pair of RCA jacks on the rear of the amplifier, to an external smartphone, computer, MP3, laptop or tablet. Connect and stream from external devices. HOME ADAPTER & MORE: The marine amp comes equipped with an AC wall power adapter that you can plug in at home. Also includes perfect audio outputs, a separate subwoofer output, volume, treble, and bass shock..