3M(TM) E-A-R(TM) Classic(TM) earplugs packaged in convenient Refill Bottles to fit your One Touch(TM) dispenser 391-1000. 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(TM) dispenser. (bul) Flame-resistant and moisture-resistant. (bul) Noise Reduction Rating (NRR)*: 29 dB CSA Class AL (bul) Test compatible with 3M(TM) E-A-Rfit(TM) 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(TM).