Dynamic over-ear headphones. With their large earpieces, the K550's wrap around your ears for total audio immersion. Thanks to what AKG call, 'Real Image Engineering', the K550's sound open, accurate and engaging - even over extended listening periods. Using large 50 mm drivers and a closed back design gives these headphones a deep, powerful bass that's also very tightly controlled and realistic. They're also lightweight and with the broad headband, very comfortable to wear. Although larger than the average headphone, the closed-back design prevents sound leakage, making them ideal for quality music on the go. The fold-flat ear cups also make them easier to pack in your bag. Frequency response: 12 Hz - 28 kHz. Sensitivity: 114 dB SPL / V. Impedance: 32 Ohm. Max. SPL: 200 mW: Weight: 305 g (without cable). Cable length: 3 m. Colour: Matte Black.