ER4XR Extended Response Earphone High performance balanced Armature drivers are precision matched to within 1 dB 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