Jiteng E320 Portable Bluetooth Speaker Rechargeable Wireless Bluetooth Speaker USB Disk Reader Connect two E320 speakers wirelessly to make two speakers 3D Sound Signal to noise ration: >70dB Power supply voltage: DC 5V Degree of separation: >70dB Power amplifier output power: 3W Frequency response: 80Hz-18KHz Supports Usb, Memory card Aux line in