This Peltor Optime 101 personal hearing protector features excellent attenuation at low and high frequencies; ear cushions (made of soft, liquid foam) that provide added comfort; and, simple height adjustment without projecting parts. The two-point suspension exerts low pressure for comfortable, long-term use. NRR27 dB Over-the Head Earmuffs * The colors of the Optime muffs allow supervisors to see from a distance if the correct muff is being used in an area. With a wide protection range that covers both severe and high noise levels, the HR earmuffs are versatile enough to meet the protection requirements of almost any working enfvironment.