3M™ Peltor™ Optime™ 101 cap-mounted earmuffs feature a stainless steel headband for consistent force and effective hearing protection. For noise levels up to 101 dBA, these cap-mount earmuffs provide effective hearing protection.- Cap-mounted design allows for easy use with most hard hats.- Liquid/foam filled ear cushions.- Color-coding for compliance sighting.- Noise Reduction Rating (NRR)*: 24 dB. CSA Class A*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™.