2 Pcs Amplifire module - PAM8403 2 Channels 2x3W Mini Digital Audio AmplifierAdvanced Micro Devices, volume: 1. 85 * 2. 11cm Excellent noise suppression in the case is not connected to the input audio, the ear close to the speaker can not hear any noise Two channel stereo, 5V power supply can output 3W +3 W power, can directly drive 4 8 small speaker output power, full of energy, good sound quality. Unique without LC filter Class D digital power board, and can be used directly to the computer's USB powered. Dual panel wiring,