Serenity Choice Music reduces the level of sound by 17dB, making music as loud as 102dB safe to listen to for up to 8 hours. They also provide a very flat frequency response so that it maintains the full sound of the music and doesn't end up sounding muffled like a traditional ear plug would. Comes with small, medium and large size sleeves to fit most ears comfortably. These Serenity Choice Music ear plugs have an SNR value of 19 dB and an NRR rating of 12 dB.