BT specification: BT V5.0 JL. Transmission range: 10 meters. Charging voltage: DC 5V. Charging time: about 2 hours. Calls / music time: 10 hours. Standby time: more than 200 hours. Output interface: 3.5mm. 145mAh A grade polymer battery. Sizes: 50 * 48 * 11.5mm, weight: 12.6g.