Etymotic Research ER4SR Reference Earphones Etymotic Research This configuration delivers a unique

This configuration delivers a unique and charming sound

making the Pro X30 the perfect choice for use on stage or other noisy environments

Compatible with Sennheiser HD380

We have succeeded in leveraging the experience of developing and manufacturing our own dynamic drive unit to draw forth the advantages of pure Beryllium

Etymotic Research ER4SR Reference Earphones Etymotic Research This configuration delivers a uniqueOverview ER4SR is the highest performing 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. The included high quality user replaceable cable is reinforced and twisted, to improve longevity and durability.