Function: Bluetooth, Handsfree, activate Siri & Google assistant Bluetooth version: 5.0 Battery capacity: 2 x 40mAh (+400mAh charging case) Earphones charging time: Approx.1.0 hours Talk/Music time: 4-5 hours (50% volume) Case charging time: 1.0-1.5 hours Bluetooth profiles: A2DP/HFP/HSP/AVRCP Impendance: 32Ω 15mW Sensitivity: 03.5 ± 3 dB Frequency response: 40Hz-20KH (Up to 10 meters working distance) Accessories: USB charging cable