The SureFire EP4 Sonic Defenders protect your hearing without interfering with your ability to hear routine sounds or conversations. The triple-flanged stem design fits larger ear canals and provides a Noise Reduction Rating of 24.Safe sound levels can pass through into the ear canal, while harmful noises (above 85 dB) are reduced via a proprietary design that incorporates a special noise-reducing filter. EP4s 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 triple-flanged stems provide secure seals in the ear canals. A low-profile design means EP4s can be worn while wearing a helmet or mask, or while using a phone or headset.Features: 24 NRR with filter caps inserted Lowers noise levels above 85 dB EarLock retention rings Hypoallergenic, medical-grade polymer Low-profile design 26" polymer lanyard included Triple flanged design for larger ear canals