Etymotic - ER4XR Extended Response In-Ear Isolating Earphones with Replaceable C

Etymotic Research

Accuracy in the midrange and high frequencies with extra presence in the lower end ACCU-Driver balanced-armature, precision-matched, custom-tuned drivers Industry-exclusive channel-matching compliance graph ACCU-Filter user-replaceable filters protect the balanced-armature drivers from ear wax Kevlar-reinforced cable for extended durability Frequency Response: 20 Hz - 16 kHz; Noise Isolation: 35-42 dB; Maximum Output (SPL): 122 dB.