Casti Akai BTE-J15 In-ear Wireless BT 5.1 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 31.5 g Base Unit Dimensions 60.12x 41.3x 27.24 mm Speaker Unit size 8 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 170mAh 3.7V Standby Time(Earbuds) 160 Hours Playing Time(Earbuds) 3.2 hours (Approx.) Charge Time (Earbuds) 1.3 Hours (Approx.) Charge Time (Charging case) 1.0 Hour (Approx.) Bluetooth Range 10 meters (open space with no obstacle) Bluetooth Transmission power ≦ 20 dBm Supported system iOS system & Android system