3M Peltor Optime I Ear Muff 27d B Sound Noise Reduction Folding-headband Ref H510F-404-GU.- Folding headb&.- Ideal for both short & long duration tasks.- Combines low profile with generous inner depth making it easy to combine with other equipment.- 27d B SNR.- Comfortable sealing rings filled with unique combination of fluid & foam.- Optime I Earmuff.- Offers versatile protection & is very lightweight providing high wearer comfort.