ER3SE Is The Highest-sensitivity Single Driver In-ear Monitor. The Iem Shells Are Made Of Anodized Aluminum, CNC Machined With Extremely Tight Tolerances. Using A Single Balanced Armature (BA) Driver Allows For Extremely Accurate IEM Without The Added Complexity Of Crossovers, And Helps Keep The Aluminum Body Small And Slim. Included Is A User-replaceable Cable. Etymotic IEMs Are World Renowned For Their Class-leading Passive Isolation, Providing 35-42 dB Attenuation (depending On Eartips Used And The Depth Of Insertion). For Comparison, Most Custom IEMs Provide Approx. 25-28dB Attenuation And Foam Ear Plugs Attenuate Up to 32 dB. The ER3SE Is Ideal For Sound Engineers, Audiophiles, And Consumers On A Budget, Who Are Looking For In-ear Monitors That Are Easy To Drive While Offering Accurate Audio Reproduction.