3M e-a-r classic uncorded earplugs, 310-1001, 200 pairs still one of the most widely used foam earplugs today, the 3M e-a-r classic earplug is an economical, reliable choice in hearing protection and conservation. Features: reusable pillow pack helps keeps earplugs clean when they are not being worn. Conforms to the shape of the earcanal to help create a comfortable, snug noise barrier slow-recovery earplug foam is flame-resistant and moisture-resistant noise reduction rating nrr: 29 db. Csa class al. Test compatible with 3M e-a-rfit validation system.