3M Peltor Optime 101 behind-the-head earmuffs fit well with most helmets, eyewear and other safety equipment.For loud environments, these behind-the-head earmuffs provide effective hearing protection. • Stainless steel band distributes weight for low-pressure fit • Earcup pivot points that tilt for optimum comfort and efficiency • Foam filled earmuff cushions • Color-coding for compliance sighting • Noise Reduction Rating (NRR)* 25 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.