EP3 Sonic Defenders protect your hearing without interfering with your ability to hear routine sounds or conversations. Their double-flange stem design fits most people and provides a Noise Reduction Rating (NRR) of 24dB. Sounds, at safe levels, are allowed to pass through into the ear canal, while potentially harmful noises (above 85dB) are reduced via a proprietary design that incorporates the patented Hocks Noise Braker® filter. EP3s include attached stopper plugs, which can be inserted for further protection, and they also block out lower-level noise like that heard on a plane. They can be used in situations where hearing ambient sounds or conversations isn't critical. The right/left color-coded Sonic Defenders are made from a soft but durable, hypoallergenic polymer and are ergonomically shaped, with an adjustable-stem design, providing a secure fit, all-day comfort, and extended product life (3 to 6+ months, depending on usage and care). And their low-profile design means they can be worn while wearing a helmet or mask, or while using a phone or headset. Each set is packaged in a convenient carry case.