A three-position muff that can be worn over-the-head, behind-the-head or under-the-chin. Includes the crown strap required for under-the-chin or behind-the-head wear. The lightweight, durable plastic construction is non-conductive, dielectric for tough environments. The large earcup openings with soft, foam-filled cushions provide excellent protection and comfort. The replaceable foam cup liners and take-apart assembly make cleaning easy and offer longer muff life. 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) when band is worn behind-the-head. ANSI S3.19-1974/CSA Z94.2.Do you order this product often and/or in large quantities? Check out our Large Order Program to save yourself time and money.