Model WJ-01 Type Mini Colors Red + Silver Quantity 1 Material Plastic Internal Memory N/A Memory Card Type Support USB flash drive / TF card Max Extended Capacity 16GB Media Format MP3 Total Power 2W Impedance 4ohm Signal to Noise Ratio(SNR) >=60dB Sensitivity 85dB +/-3 dB Channels 2.1 Remote Type N/A Interface 1 x USB 2.0 1 x Mini USB 1 x TF card slot 1 x 3.5mm jack Radio FM Radio FM Frequency 87~108MHz Power Supply Built-in Rechargeable Battery Built-in Battery 500mAh Other Features 1 inch display screen. Packing List 1 x Speaker 1 x USB data cable (40cm) 1 x Chinese / English user manual 1 x Battery