... Jack High-Fidelity Magnetic Speakers Noppal 768 Portable Active Mini Speaker For Micro SD/TF Card, MP3, Mobilephone, ... files in usb disk,micro SD/TF card .2) Can be connected to to mobile phone/mp3 ... volume.Output power: RMS: 3W*2 THD=10%Frequency Response:150-18KHzLoud Speaker:3W; 4ΩSignal and noise ... 4.2VInput: 5.0V Noppal 768 Portable Active Mini Speaker For Micro SD/TF Card,MP3,Mobilephone,PC