Etymotic ER4XR Extended Response Earphone

High performance Balanced Armature drivers are precision matched to within 1 dB, Transducers: Single high-performance balanced armature per channel., Specially designed for uncompromising accuracy in the mid to high frequencies with a bit of extra presence in the lower end, Sleek, anodized, laser etched aluminum body and braided, reinforced detachable 5 ft. Cables with custom MMCX connectors, 35-42 dB of noise isolation with a max output of 122 dB