Provides optimum hearing protection. Earplugs are properly inserted when the fitting ring on the earplug is no longer visible. Moisture resistant and dermatological safe foam is not irritating. Slow recovery foam provides comfort. Meets ANSI S3.19-1974 standards. Tapered style earplugs are laboratory tested and have a Noise Reduction Rating, NRR 33dB. Use refills with E-A-R One Touch earplug dispenser Made in the USA.