SureFire EP3 Sonic Defenders are filtered flanged earplugs that protect hearing without interfering with the ability to hear routine sounds or conversations. The patented EarLock retention rings lock the earplugs into place, while soft, adjustable double-flanged stems provide secure seals in the ear canals. The 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. The attached filter caps can be inserted for additional protection or to block out lower-level noise when hearing ambient sounds or conversations isn't critical. Each pair of earplugs is packaged in a convenient carry case and includes a polymer lanyard.