Hearos Xtreme Protection Ear Plugs 28 pairs (Pack of 4)

Pack of 4 for the UPC: 756063054275 Xtremely High NRR 33Noise Reduction Rating 33 Decibels (when used as directed). The range of noise reduction ratings for existing hearing protectors is approximately 0 to 30 (higher numbers denote greater effectiveness.Tested according to ANSI Specs S3.19-1974 The level of noise entering a person's ear, when hearing protector is worn as directed, is closely approximated by the difference between the A-weighted environmental noise level and the NRR.