High-performance dual speakers drive with Aluminum metal body. Bluetooth 4,0 / NFC / Line-in. Built-in 650mAh Li-polymer battery. Standby time: 300 hours; Music play time: 4 hours. Can be used as a hands-free kit with talk time up to 6 hours. Charging time: 2 hours. Speaker battery display on mobile device. Built-in Microphone. Frequency Range: 100 Hz to 20kHz. S/N: 60dB. What's in the box 1 x Remax Music Eyes Bluetooth Speaker 1 x Micro USB Charging Cable 1 x 3.5mm Auxiliary Cable