3M™ E A Rflex™ 28 features soft, E A Rform™ 28 foam tips that reacts to body temperature for enhanced comfort and fit. Pivoting tips for proper, comfortable fit that moves with the wearer for more consistent protection. Replaceable foam tips: product number 320 1001 Noise Reduction Rating (NRR)* 28 dB. CSA Class AL. *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™.