3M™ PELTOR™ Optime 101 Earmuffs H7A help provide effective hearing protection and are designed for noise levels up to 101 dBA. It provides consistent force to keep the earcups snugly in place yet with a low pressure fit that is more comfortable. Features Noise Reduction Rating (NRR)*: 27 dB. CSA Class A Fit can be verified with 3M™ E-A-Rfit Dual-Ear Validation System Replaceable ear cushions and foam liners (3M™ PELTOR™ Hygiene Kit HY7)