These incredible rechargeable wireless headphones are great for listening to your music while on the move. Pair via Bluetooth with your smart device and control your media with the MP3 function control keys on the edge of the earcup. Alternatively play MP3 or WAV media files from a micro SD card using the slot in the side of the earcup. In-built is an FM radio and a microphone allowing hands free calls. These headphones offer a fantastic listening experience with dynamic bass technology. The noise cancelling feature blocks out background noise making them perfect for cutting out low noises from planes or trains. They have an internal rechargeable battery with up to 8 hours playback. Speaker size: 40mm dome. Frequency response: 12Hz - 22kHz. Sensitivity: 108dB/mW. Impedance: 32 Ohms at 1kHz. Connections: Bluetooth, 3.5mm stereo jack, micro USB for charging. Weight: 142g.