3M e-a-r classic earplug, corded, 311-1101, 200 pairs still one of the most widely used foam earplugs today, the 3M e-a-r classic earplug is an economical, reliable choice for hearing protection and hearing conservation. Slow recovery, low-pressure foam conforms to the shape of the earcanal to help create a comfortable, snug noise barrier. Features: poly bag keeps each pair of disposable earplugs available or accessible for re-use. Flame-resistant and moisture-resistant. Corded for easy short term storage around the neck. Noise reduction rating nrr: 29 db. Csa class al. Test compatible with 3M e-a-rfit validation system.