3M™ Peltor™ H10P3E Optime earmuffs provide excellent hearing protection and are meant to attach to your hard hat for a noggin - saving, hearing - prolonging duo. These earmuffs have a dual cup design that provides effective hearing protection.The 3M™ Peltor™ H10P3E earmuffs have a 27 Noise Reduction Rating (NRR 27 db)