ONKYO semi-open wireless headphones Bluetooth / NFC support / control with microphone E300BTB (Black) Transmission scheme: Bluetooth standard Ver.4.1 / corresponding Bluetooth profiles: A2DP, AVRCP, HSP, HFP / corresponding codec: SBC, aptX / multi-pairing: up to four Power: 120mAh, built-in rechargeable lithium polymer battery / battery duration :( continuous communication) Music playback time: up to 7.5 hours / call time: up to 8 hours / Continuous standby time: up to 170 hours / charging time: about 2 hours Format: semi-open / driver size: 8.6mm / reproduction frequency band: 7-25,000Hz / output sound pressure level: 108dB / impedance: 16 Mass: 15g (including code) Accessories: earphone chip (silicon) S, M, L (2 each) / micro USB cable (1m) / Japanese manual