High performance headphones with clear, rich stereo music. Wireless built-in BT receiver allows you to wirelessly connect your iPad, iPhone, iPod, Android tablet, HDTV, laptop, MP3 player & more. Built-in FM radio. Built-in microphone allows you to talk when you make a phone call. Aux 3.5mm input: gives you the option to connect to non-BTdevices. Built-in micro USB input for charging. Built-in micro SD card slot. Adjustable folding design with soft head band and soft-cushioned earcups. Music volume control directly on the headphones. Noise reduction. Built-in rechargeable battery. Duration: music 4hrs/talk 4hrs./Standby time:180hrs./Charging time: 2hrs. BT Version: V 4.2 JR. Drivers: 40mm. Impedance: 32ohm. Sensitivity: -80dBm. Frequency Response: 20Hz-20000Hz. Frequency Range: 2.4GHz - 2.48GHz. Transmission Distance: 33FT. Battery Voltage: 250mAh. Battery Charging Voltage: DC 5V 0.5V. Black.