MT-S28 ,Notebook 2.0CH Speaker USB Power supply . CE/Rohs MOQ: 3000pcs ♦ Innovative low-frequency radiation ... and CD, etc.♦ Green materials, environmental protection and energy savingPower: USB DC5V THD+N (Amplifier): <=0.2%Input sensitivity: 550±50mV ... -20kHz Driver unit: 1.5inch*2 ,4ohmSignal to noise ratio (Amplifier): >=95dBAConnect by USB and audio, For PC ,notebook ,MP3... *Built in low ...