NRR 27. 3M™ Peltor™ Optime™ 101 over-the-head earmuffs feature a stainless steel headband for consistent force and effective hearing protection. For noise levels up to 101 dBA. Stainless steel headband distributes weight for low-pressure fit. Earcup pivot points that tilt for optimum comfort and efficiency. Liquid/foam filled earmuff cushions Noise Reduction Rating (NRR)*: 27 dB. CSA Class A. ... More Info >