These push to fit, corded foam uncorded earplugs are easy to use again and again, reducing waste. Proprietary no roll down Poly bag keeps earplugs clean before use Blue stem makes fitting and removal cleaner and easier. Noise Reduction Rating (NRR)*: 28 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™.