Slow recovery, low pressure foam fits snugly to create a noise barrier that helps protect hearing from loud sounds. The earplugs are both flame resistant and moisture resistant. Bright yellow color allows supervisors to conduct a quick visual hearing protection compliance check. Use when exposed to noise such as in assembly and mechanical, chipping, chiseling, cleaning, drilling, furnace operations, grinding, heavy equipment operations, machining, metal repair, painting, pouring/casting, power fastening, riveting, sanding, sawing and welding and more. Test compatible with the 3M™ E-A-Rfit™ Validation System. These earplugs have a Noise Reduction Rating (NRR) of 29 dB, CSA Class AL. 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, and motivation of the user. It is recommended that the NRR be reduced by 50% to better estimate typical workplace protection.