3M E-A-R Classic Earplugs set the standard in hearing protection as the world's first foam earplugs. Slow recovery, low pressure foam conforms to the shape of the ear canal for enhanced comfort and wearability. Moisture-resistant helps maintain a consistent expansion time, even in humid environments. Noise reduction rating (NRR) 29 dB. CSA Class AL. Flame resistant0important for potential arc flash situations and for storage considerations.