Bluetooth transmitted modulation: GFSK, π/4DQPSK, 8DPSK Bluetooth frequency: 2.402 GHz – 2.48 GHz Bluetooth profile version: A2DP 1.3, AVRCP 1.5, HFP 1.6 Bluetooth version: 5.0 Headset battery type: Coin cell battery (55 mA / 3.7 V) Charging case battery type: Li-ion polymer battery (450 mA / 3.7 V) Charging time: < 2 hrs from empty