QB2HYG® Supra-Aural 25 dB. Ergonomic design keeps the pads suspended so they don’t become contaminated. Available in three different plug styles: QB1HYG® inner-aural protection has the highest NRR 27 dB rating. QB2HYG® supra-aural protection has a NRR 25 dB rating. QB3HYG® semi-aural which is designed for moderate or intermittent hearing protection has a NRR 23 dB rating.