Mack s Original Soft Foam Earplugs are molded with state-of-the-art super low-pressure skinned and tapered foam. These special features provide unmatched comfort and improved hygiene. With a noise reduction rating (NRR) of 32 decibels Mack s Original Soft Foam Earplugs can be used in environments where noise is just a nuisance up to environments with hazardous noise levels. For sleep study work shooting travel power tools loud events etc. (30 pair).