EP4 Sonic Defenders Plus protect your hearing without interfering with your ability to hear routine sounds or conversations. Their triple-flanged stem design fits larger ear canals and provides a Noise Reduction Rating (Nrr) of 24d B. Sounds, at safe levels, are allowed to pass through into the ear canal, while potentially harmful noises (above 85d B) 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 Plus 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 Ear Lock 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. Available in clear, black, or orange. Comfortable EP4 Sonic Defenders Plus also serve as earpieces for compatible radio communication systems* simply by removing the noise-reducing filter and attaching the earpiece to the system. Note: EP4 earpiece no longer provides hearing protection once the noise-reducing filter has been removed.