SMAKN&reg; PAM8406 MiNi Amplifier Board(5W+5W) D Class Amplifier Board Supermicro volume: 23 * 24MM , weight 0.45 g Excellent noise suppression, in the absence of access input audio, ear close to the speaker did not hear any noise The two-channel stereo, 5V power supply can output 5W + 5W power, can directly drive 4, 8 speakers, output power, full of energy, good sound quality, with left and right channel volume control. Rated working voltage: 2.5-5V, limit operating voltage :5.5V