POLYBAG Corded, Red Vinyl Qty/Box: 100 prs. 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. Outstanding noise-blocking protection – highest attenuation in multiple-use. Attenuation tested in accordance with ANSI S3.19-1974. Rating: NRR 27 dB, CSA Class AL.