EP3 Sonic Defenders protect your hearing without interfering with your ability to hear routine sounds or conversations. Their double-flanged-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 a special noise-reducing filter. EP3s include attached filter caps, which can be inserted for additional protection and blocking out lower-level noise, like that heard on a plane, where hearing ambient sounds or conversations isn't critical. Right / left color-coded Sonic Defenders are made from a soft but durable, hypoallergenic polymer that provides all-day comfort and an extended product life (up to 6+ months, depending on usage and care). Their patented EarLock retention rings lock the earplugs in place, while soft, adjustable double-flanged stems provide secure seals in the ear canals. A low-profile design means EP3s can be worn while wearing a helmet or mask, or while using a phone or headset.