Type: Bluetooth speaker Connection method: Bluetooth connection Interface type: USB Battery capacity: 1500 mAh Frequency response range: 100HZ-20KHZ Output power: 5W Signal to noise ratio: ≥75dB Power supply: built-in lithium battery Channel: 2.1 Playing time: 4h Expansion storage: 32GB Bluetooth protocol: 4.1 Number of speakers: 2