Sony MDR-V700DJ Studio Monitor Series DJ Headphones Studio Monitor Series Headphones incorporate high-end materials and advanced engineering; critically clean, exceptionally clear sound for professional and high fidelity applications Swivel earcups for DJ and remix applications enable single-sided monitoring. DJs can listen to house sound with one ear while they cue up the next track with the other. Convenient for on-shoulder use. Reversible earcups for even greater monitoring flexibility Auto return swivel mechanism brings the earcups back to standard listening position -- another nice touch from Sony 50 mm diameter drive units for reference-grade sound; enable superior power handling; deeper bass, lower distortion and wider dynamic range; frequency response extends down to an extraordinary 5 Hz