3M™ earmuffs feature durable, lightweight construction of non-conductive, dielectric plastic that can be worn over-the-head, behind-the-neck or under-the-chin. Benefits •These lightweight earmuffs may be worn over-the-head, behind-the-head, or under-the-chin. •Large earcup openings and soft, foam-filled cushions offer a snug, comfortable fit. •Durable, lightweight construction of non-conductive, dielectric plastic. •Noise Reduction Rating* NRR 25 dB (CSA class A) when the band is worn over-the-head. NRR 26 dB (CSA Class AL) when the band is worn under-the-chin. NRR 26 dB (CSA Class AL)