Their unique performance results from the perfect balance between the noise-isolating qualities of a closed-back headphones and the spacious, dimensional sound of an open-back design. The 50mm drivers provide a strong, yet accurate and distinguished bass response as needed for monitoring and mastering contemporary music. The extra large, soft ear pads ensure stress free listening over hours and the 2D-axis mechanism enables full flat folding for easy storage or handling on the road. With its low impedance drivers the K553 PRO is sensitive enough to also be used on laptops and mobile devices, so the soft high quality cable is equipped with a 3.5mm (1/8) plug. A screw on adapter to 6.3mm (1/4) is included. Features: Lightweight Over-ear design for maximum wearing comfort over hours of continuous listening. Advanced closed-back technology for high noise insulation. Advanced closed-back technology for high noise insulation. Low impedance for impressive performance on any portable device. 2D-axis fold-flat mechanism for easy storage and transportation.