Moisture and flame resistant. Slow-recovery foam provides comfortable, effective seal while exerting low pressure in ear canal. fit wide range o ear canals. Classic™ Plus are slightly longer than regular E-A-R™ Classic™ Earplugs to fit deeper into the ear canal and provide higher noise reduction. Test compatible with 3M E-A-Rfit™ Validation System 2,000 Pair/case.