This board is a tiny power amplifier board designed with VMA2015 - It has one stereo audio input jack 1 power supply connector and 2 speaker connectors - There's one jumper for enable signal and tow for gain setting for VMA2015 - With the outstanding performance of VMA2015 audio amplifier module it can drive 2 8 Ohm speaker to unbelievable 15W per channel! - You just can't believe this small board can singing that loud - The noise is very low and sound quality is excellent (0.07% THD+N) - Ultra small size makes it very easy to fit in any speaker boxes to build an active speaker