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.