Elvex Equalizer Muff, SuperSeal, 27dB NRR, 8.5 oz Weight 27 dB Certified NRR to ANSI S3.19-1974 A flexible inner headband aligns automatically to the shape of the head Fully dielectric construction Pressure equalizing headband provides even fit and seal for a wide variety of facial configurations and sizes SuperSeal ear cushions provide outstanding seal and comfort