Sony - XB950BT Wireless Over-the-Ear Headphones - Limited Edition -Titanium Over-the-ear design; Bluetooth 3.0 interface with NFC (Near Field Communication) technology Rechargeable battery; Built-in microphone; 40mm drivers; 3Hz - 28kHz headphones frequency response 24 ohms impedance; Dynamic transducer design; 102dB/mW sensitivity; Stereo design