The High dB Filter for our High Fidelity Earplugs is an upgrade from the standard High Fidelity Attenuation Filter that comes with our High Fidelity box packages. The High dB filter provides up to 27 dB of noise reduction versus the 21 dB in reduction our standard Attenuation Filter. This is a great option those looking for a bit of extra noise reduction, while still maintaining sound clarity!Please note the High dB filter is only compatible with our High Fidelity Earplugs and is not compatible with any other products in our catalog such as our Smaller Ears Earplugs.