Excellent for: sleeping, studying, travel, blowdrying, lawn mowing, power tools, concerts, sporting events Nrr33. Noise reduction rating: 33 decibels (when used as directed). The range of noise reduction ratings for existing hearing protectors is approximately 0 to 30 (higher numbers denote greater effectiveness). 10 pair And carrying case Noise reduction rating: 33 decibels (when used as directed) Smooth, tapered design; soft comfortable fit