Converts to any 3.5 mm stereo headset or portable speaker Dimensions: 40mm Built-in Lithium-ion battery 3.7V With 3.5mm jack audio cable Power output : RMS 1.5W THD+N1% Frequency response : 50Hz-20Hz Input voltage : DC 5V 500mA Speaker unit : 27mm 4 2W Built-in battery : Lithiun-ion battery SNR : >90dB Response sensitivity : 90dB Case materrial : Pure ABS Dimensions : 40mm Weight : 50g