Sony MDR-V900HD Monitor Series Headphones with Reversible Earcups (Discontinued by Manufacturer) Designed & Engineered For High-End Applications Large, Aura-Nomic Design 50Mm Driver Units High-Definition Driver Units Reproduce Up To 80 Khz Convenient Folding Design With Supplied Carrying Case Reversible Earcups For Single-Side Monitoring Circum-aural design for excellent sound and listening comfort Oxygen-free copper voice coil provides high power handling capacity (3000 mW) 50 mm diameter drive units are positioned on ear canal for natural sound Concealed, single-sided, oxygen-free copper cord is 10feet long (3 meters) Swivel earcups are also reversible; comfortable single-sided monitoring