Soft, roll-down foam earplugs expand to fit the earcanal & provide a low-pressure, comfortable seal. Poly bag keeps each pair of earplugs clean before use. CSA Class AL. Test compatible with 3M E-A-Rfit Validation System. However, research suggests that many users will receive less noise reduction than indicated by the NRR due to variation in earplug fit, earplug fitting skill, & motivation of the user. It is recommended that the NRR be reduced by 50% to better estimate typical workplace protection. Corded / Cordless: Cordless; Shape: Tapered; Material(s): Polyurethane; Noise Reduction Rate (NRR): 32 dB.