Enjoy big sound without cables with theJBL E55BT Bluetooth Over-Ear Headphones. These headphones connect to your mobile device using Bluetooth 4.0 and sport 50mm drivers, which deliver a frequency response from 20 Hz to 20 kHz with 32 Ohms of impedance. Music controls and a microphone are located on one earcup for convenient control over your calls and music, and the included fabric-covered cable with angled plug has a remote and mic of its own. The E55BT can seamlessly switch between connected devices and last for up to 20 hours on a fully charged battery, which takes approximately two hours to replenish.50mm DriversBluetooth 4.0 Wireless ConnectivityFrequency Response: 20 Hz to 20 kHzImpedance: 32 OhmsOn-Ear Controls with Microphone