Features 1.MULTIFUNCTIONAL: Subwoofer speaker amplifier board is with the pre amplification, bass divider processing. 2.SUPPORT FUNCTION: 2.1 power amplifier board with bass, left and right channel volume adjustment, treble adjustment, total volume potentiometer control. 3.HIGH POWER: Power amplifier module is using DC 12?24V power supply, Maximum support 50W(Left CH) and 50W(Right CH) and 100W(BASS CH) three channel output. 4.POWER SAVING: Super bass speaker amplifier board has wide operating voltage, power saving design, the efficiency of up to 90% or more. 5.ANTI SHOCK PROTECTION: Digital sound amplifier board with boot anti shock protection design, boot no burst sound. specificationItem Type: Subwoofer Speaker Amplifier Board Material: PCB Core Chip: TPA3116D2 Operating Voltage Range: DC 9?25V (current 3?4A Or Higher, If More Power Is Needed, 19?24V 4?5A Or Higher Is Recommended) Sound Input Sensitivity: 500?800mV Frequency Response Range: 20Hz to 20KHz Speaker Impedance: L R CH Speaker 3.5?8 BASS Speaker: 2?8 Maximum Output Power: 50W (L CH), 50W (R CH), 100W (BASS CH) Size: Approx. 101x100x30mm/3.97x3.94x1.18in PackageList 1 x Power Amplifier Board 4 x Screws 4 x Studs 1 x 3Pin Cable NotePlease allow 1?3mm differs due to manual measurement.