The world`s first foam earplugs and still the most widely used cylindrical earplug today. Packaged in convenient Refill Bottles to fit your One Touch™ dispenser. - Flame-resistant and moisture-resistant. - Noise Reduction Rating (NRR)*: 29 dB CSA Class AL - Test compatible with 3M™ E-A-Rfit™ Validation System *The NRR may overestimate the hearing protection provided during typical use. 3M recommends reducing the NRR by 50% for estimating the amount of noise reduction provided. 3M is Leading the Advancement of Hearing Conservation™.