Conforms to EN 352-3 H=40 M=32 L=22 SNR=34. * Optime III is a super-muff, and has been developed for use in extremely noisy environments. * The protection is based on new technology with a double casing that minimises resonance in the holder casing. This results in maximum high-frequency muffling, while at the same time it's still easy to understand speech and signals. * An acoustic connection between the inner volume and the volume between the casings in its turn provides maximum low-frequency muffling. * The sealing rings are broad and filled with soft plastic foam for the best fit and low contact pressure.