Sony MDR-G94NC Street Style Noise Canceling Headphone Noise-canceling technology reduces outside noise by up to 70 percent 30 mm diameter drive units provide deeper bass, lower distortion and wider dynamic range Oxygen-free copper cord conducts electricity better than conventional copper for maximum conductivity and minimum noise Handy, behind-the-neck, folding headband keeps out of the way Gold-plated mini-plug resists corrosion and brings maximum conductivity with minimum noise