Our High Fidelity Earplugs come with a 21dB filter pre-inserted in the Standard size earplugs in the set; we also recently released a 27dB filter , so you could switch the filters out between the two. Please note that the aforementioned filter is only available for our High Fidelity Earplugs model- not our Smaller Ears Earplugs.Our Slide Earplug has this functionality pre-built into it; it has a slider that enables the user to switch between two levels of attenuation, from 15 to 22dB.