The HD668B is a semi-open dynamic headphone whose sound quality meets the demands of even professional recording studios. Its patented sturdy construction provides long-lasting durability even in challenging conditions, yet the headband's light weight andoptimized mechanical pressure provides long-term wearing comfort. The HD668B reproduces natural, spatial and accurate sound for all types of music. It features a balanced, contoured and bass enhanced full range frequency response with authentic mid range and high frequency reproduction. HD668B comes equipped with two detachable straight cables: the short one is one meter long for personal sound source applications and the long one is 3 meters long for professional monitoring applications. Both cables can be connected together for even more distance if desired. Shipped with a protective storage pouch and gold-plated 3.5mm to 1/4 inch snap-lock adapters, the Superlux HD668B headphones are an excellent choice for a wide range of audio listening tasks and applications.