Details of the M90 headphones: Bluetooth version : V5.0 + EDR (automatic connection) Bluetooth protocol : A2DP1.3 / HFP 1.6 / HSP1.2 / AVRCP1 6 / D113 Bluetooth frequency : 2.4G Battery capacity: headphones 50 mA Effective Bluetooth distance: 10 meters Music playing time: about 4-5 hours Talk time: about 4 hours Charging time : 1-2 hours Headphone weight: 115 grams LED screen shows the remaining battery 1When it is connected for the first time Can be connected to the phone automatically when the headphones are turned on