Power supply: USB 5V Built-in battery: BL-5C 860Mah Speaker power: 3W Frequency: 80-18KHz Signal-to-noise ratio: ≥ 85db Duration: 4 to 8 hours Size: 24mm (W) * 47.5mm (H) Features: 3.0 Bluetooth function, USB decoding, TF card, FM radio call feature