Brand No Model GF-007 Quantity 1 Color Green Material FR4 Features Excellent in noise control in the case is connected with the input audio there is no any noise even we close the speaker when there is not input audio; Two channel stereo 5V power supply it can output 3W+3W power and can drive 4 ohm 8 ohm small speaker directly it is with large output powerenough energy and good sound quality; Class D digital power board without LC filter is unique and can be charged by wiring the potential balance and inter-channel; Ultra micro design can make it be easily placed inside of various digital products it is with amplification efficiency; Note: the negative of the right channel output can not be connected together otherwise it will burn IC and we should connect the speaker before power is switched Specification Input voltage: 2.5~5V; Powered by USB Application single-chip systems experiment English Manual/Spec Yes Packing List 1 x Mini amplifier board