Hearing loss from loud sound affects millions of people, but noise-induced hearing loss is preventable! Er20Xs high-fidelity earplugs reduce sound levels while preserving sound quality and clarity. Er20Xs earplugs are configured to replicate the natural response of the ear, so sound quality is the same as the original, only quieter. Music, voices and other sounds are clear--not muffled--making Er20Xs ideal for concerts, clubs, theaters, aircraft, construction, yard work, airshows, parades, and athletic or motorsports events. The new low-profile, stem-less design fits snugly in the outer ear without protruding, making Er20Xs comfortable to wear under hats, helmets, and other headgear. The standard-size eartips fit the majority of ears. Er20Xs earplugs are reusable, but with repeated use, the eartips may lose elasticity. For best performance and retention, if you use your Er20Xs earplugs frequently, replace the eartips every 3-6 months. Er20Xs are not recommended for use with impulse noises such as gunfire, or for sleeping. The new Er20Xs is the highly-awaited next generation of Etymotic's industry-leading ETYPlugs High-Fidelity Earplugs. Er20Xs eartips are interchangeable. Er20Xs earplugs can also be used with foam eartips with essentially no change in response. Er20Xs earplugs are discreet and have the identical response of ETYPlugs through 4 k Hz. Above 4 k Hz they have improved high-frequency clarity without compromising protection. Er20Xs earplugs feature a low-profile, stem-less design that sits snugly in the outer ear without protruding. This makes it especially comfortable to wear under hats, helmets and other headgear. Er20Xs earplugs come with a small, flexible pull tab that allows for easy removal, an easy-to-install neck cord and a carrying case.