Shure SRH1440 Professional Open Back Headphones (Black) 40 mm neodymium drivers deliver full-range audio with rich, controlled bass Open-back, circumaural design for exceptionally natural sound, wide stereo image, and increased depth of field Impedance optimized for direct connection to wide range of portable audio devices Fully adjustable, premium padded headband with steel frame and sleek, ergonomic design for hours of listening comfort Oxygen-free copper cable with Kevlar reinforced jacket for superior performance and durability