Bluetooth: V5.1 Bluetooth protocol: A2DP 1.3 ,(HFP)1.6,(HSP)1.2, AVRCP Frequency range: 20 Hz – 20,000 Hz Charging time: approx. 1 hour Indicator light: RGB LED tricolour light :1.Charging status indicate; 2. Charging box/battery life indicate;3.Charging box in low power; 4.Recover factory setings indicate. Charging port: via Charhing box Pogo Pin 55mAh, Lithium ion button battery.