SMAKN Finished board-New subwoofer 2.1 TPA3123 digital power amplifier board for DIY Power supply: Voltage:12-24V (Suggest 15V-20V) It's better to use high quality switching power supply. The maximum output:Left/Right output: 20WX2 subwoofer output:40W DimensionWidth x Dept x Hight(82mm*65mm*30mm) (The dimension do not include the potentiometer handle & other Projecting part) Input hole spacing distance of the amp board2.5mm Distance between 2 Potentiometers:5mm