Headband headphones bluetooth headphones type of fitting on ear transmission mode cordless features collapsible control via headset microphone functions nfc rechargeable remote control function sound function passive noise reduction sound mode stereo range 10 m bluetooth button position on headphones impedance 24 ohm frequency response 20 20000 hz driver 30 mm number of drivers 1 operating time 8 h talk time 8 h battery charging time 2 5 h