3M™ Peltor™ Optime™ 105 Cap-Mount earmuffs for noise levels up to 105 dBA, these earmuffs with double-shell technology provide optimal protection. The OPTIME 105 features added mass and volume, plus a unique “double-shell” earcup design (two cups connected via a foam inner layer to reduce structural resonances) to provide the maximum in noise reduction throughout the full range of low and high frequencies.