I use this with the WM1A.
Improved sound quality with technology inherited from the Signature Series MDR-Z1R’s
Newly developed 70mm driver unit, aluminium-coated Liquid Crystal Polymer diaphragms, bigger magnets and a Fibonacci-patterned grill
Superb sound quality with a three-dimensional, spatial sound experience that delivers wide spacious sound from 4 Hz to 100kHz
Ear pads made of very thick low repulsion urethane foam reducing pressure and providing long-wear comfort