3M™ Peltor™ Optime™ 105 behind-the-head earmuffs features low-profile earcups that fit well with most helmets, Feature double-shell technology for effective hearing protection. For noise levels up to 105 dBA, these behind-the-head earmuffs feature double-shell technology to provide effective hearing protection.3M recommends reducing the NRR by 50% for estimating the amount of noise reduction provided

• Patented Twin-Cup™ design has soft, foam-filled earmuff cushions.
• Behind the head design allows for easy use with hard hats
• Liquid/foam filled earmuff cushions
• Color-coding for compliance sighting.
• Noise Reduction Rating (NRR)*: 29 dB. CSA Class AL