Ear Plugs SONIC DEFENDER PLUS - Medium One Pair EP4 Sonic Defenders Plus® Filtered Flanged Earplugs 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 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. Available in Medium and Large. Size Medium fits most people. Click on "Images/Articles" tab above for sizing information.