The Superlux closed-back, circumaural HD661 headphone is designed for live sound monitoring applications. Its accurate frequency response and spatial depth of field make it suitable for studio and broadcast applications as well as general music appreciation, producing a natural accurate sound for all types of music. The closed-back design makes it particularly useful in high noise environments or situations requiring limited audio leakage from the phones. The balanced, high definition and clear sound of the HD661 provides the confidence needed when recording or monitoring. It features a rotating ear pad for single-ear monitoring when required. The patented self-adjusting headband structure provides long-lasting durability, while its light weight optimized mechanical pressure provides long-term wearing comfort. The HD-661 comes equipped with two detachable straight cables; a short one for personal sound source applications and a long one for professional monitoring applications. The cables can be connected together for even more distance if desired. The HD-661 includes a soft protective storage pouch, gold-plated 3.5mm to 1/4" phone snap-lock adapter and a cable retention clip.