Casti Akai BTE-J101 In-ear Wireless BT 51 Chipset JL AD6983D Bluetooth Version V5.1+BR+EDR+BLE Bluetooth Frequency 2.4-2.485GHz Audio decoding SBC/AAC Profiles supported a2dp/avctp/avdtp/avrcp/hfp/spp/smp/att/gap /gatt/rfcomm/sdp/l2cap profile Weight 30 g Base Unit Dimensions 50.1 x 48.4x 23.2 mm Speaker Unit size 13 mm (dia.) Charging Input 5V 320mA Microphone Sensitivity －42±3dB Frequency Response 20Hz-20000Hz Built in Battery type (Earbuds) Lithium 30 mAh 3.7V Built in Battery type(Base Unit) Lithium 220mAh 3.7V Standby Time(Earbuds) 160 Hours Playing Time(Earbuds) 3 hours (Approx.) Charge Time (Earbuds) 1.3 Hours (Approx.) Charge Time (Charging case) 1.4 Hour (Approx.) Bluetooth Range 10 meters (open space with no obstacle) Bluetooth Transmission power ≦ 20 dBm Supported system iOS system & Android system