Bluetooth chipset: JIELI6963 BT version: V5.0 Frequency response. 20Hz-20KHz Battery capacity of the earphones: 30mAh x 2 Battery capacity of the charging case: 200mAh Working time: 4 hours Working distance: ≥ 10M Earphone charging time: 1 hour Charging time of the charging case: 1 hour Earphone charging time: 2 times Colors: Black, White