... function OEM service Magnetically shielded 4.1 multimedia speaker system,card speaker,square speaker 1.Hot 4.1 home theater speaker ... , solemn and delicate overlook.2.With USB/SD card read,and FM function, remote control.3. 5.25" composite ... , high intensity, effectively eliminate resonance and cabinet noise5. With Standby,Input,Menu,VOL+,VOL- keys on the front panel. Output power20W ...