Elvex EP-411 Quattro ear plugs are a universal size reusable ear plug designed to be used over and over again while maintaining comfort and effectiveness. These ear plugs have a four flange design that allows it to fit in almost all ear canals. This is an ultra-soft polymer that provides a comfortable and effective seal. There is a sturdy and stiff handle that allows an easy grip for insertion and removal. The material is resistant to ear wax and body oils and they will outlast PVC ear plugs by many months. The polymer material is non-allergenic and non-irritating to the sensitive skin in the ear canal. The noise reduction rating is 25db and the test was performed to ANSI S3.19-1974 at an independent and certified laboratory, NVLAP #4027. The Quattro has been assigned U.S. military national stock numbers. These Elvex Quattro ear plugs are corded and they are packaged in individual poly-bags. There are 100 per dispenser box and there are 4 boxes in a case.