Product information : Function: card, voice prompt, call function Speaker unit double: speaker Type: bluetooth speaker Connection method: Bluetooth connection Interface type: USB Frequency response range: 100HZ-20KHZ Built-in battery capacity: 2000mAh-4000mAh Output power: 10W Signal-to-noise ratio: ≥75dB Power supply method: built-in lithium battery Shell material: plastic Box material: ABS Colour: Black Size Information: Appearance size: 350*102*60mm Packing list: Speaker*1+charging cable*1+audio cable*1+packaging box*1