Sonic Defender Plus passive hearing protection against potentially damaging sound: Internal Hocks Noise Braker filters allow normal ambient and conversational sounds to pass through while blocking potentially dangerous sounds of 80 dB or higher. Made from a soft, hypoallergenic polymer that permits extended wear time, the right / left color-coded EP4 Sonic Defenders lock into the outer ear folds, and their triple-flanged stem fits snugly in the ear canal. Their low-profile design makes them usable beneath a helmet, mask, hat, or while using a telephone or headset.