Microlab B51 Portable USB-Powered Clip-on Speakers with 3.5 mm Jack Driver: Speaker driver: 1.5 x 2 Frequency Response: 80 Hz - 18 kHz Signal to Noise Ratio(SNR): > 65 dB Color: Black Impedance: Speaker: 4 ohms Power Supply: USB: 500 mA via DC5V adapter Dimension: 2.68 x 8.07 x 1.38 (H x W x D)