Shure SRH840 Professional Closed-Back Reference-Class Studio Headphones. Designed for professional audio engineers and musicians, the SRH840 Professional Monitoring Headphones from Shure are optimized for studio recording and critical listening.  A precisely tailored frequency response and 40mm neodymium dynamic drivers combine with total comfort and durability to provide the ultimate listening experience.  The replaceable headphone cable and set of replacement ear pads included ensure a long lasting lifetime of use.