Advanced air pocket design features internal noise-blocking fins. Four-flange profile creates better seal in the ear canal. Less pressure in the ear canal eliminates that "plugged up" feeling. Rounded flanges, tapered shape fits better in the ear canal. Firm stem facilitates easy insertion and removal. Corded/Cordless Pair: Corded; Shape: Flanged; Material(s): Molded Foam; Noise Reduction Rate (NRR): 27 dB.