Noise Reduction Rating 24 Decibels Allows You to Turn Protection Off When NeededEPA  Noise Reduction Rating: 24 Decibels closed, 4 Decibels open (when used as directed). The range of noise reduction ratings for existing Hearing protectors is approximately 0 to 30 (higher numbers denote greater effectiveness) PROTECHS™ Flip to Listen® Ear Plugs have a dual mode, allowing with a flip to easily switch from a closed to open position without the inconvenience of removing. These ear plugs are durable, reusable and can remain comfortably in place for hours. Information required by EPA: The level of noise entering a person's ear, when a hearing protector is worn as directed, is closely approximated by the difference between the A-weighted environmental noise level and the NRR. Example closed:  (1) The environmental noise level as measured at the ear is 92 dBA. (2) The NRR is 24 decibels (dB).  (3) The level of noise entering the ear is approximately equal to [92 dB(A) - 24] 68 db(A). Example open:  (1) The environmental noise level as measured at the ear is 92 dBA.  (2) The NRR is 4 decibels (dB).  (3) The level of noise entering the ear is approximately equal to [92dB(A) - 4] 88 db(A). The range of noise reduction ratings for existing hearing protectors is approximately 0 to 30 (higher numbers denote greater effectiveness).