Foam polyurethane Highest noise reduction rating of any single-use earplugs; the world's most used polyurethane foam earplug Bell shape matches contours of your inner ear to ensure maximum noise reduction and resist tendency to back out of ear canal Smooth, soil-resistant closed-cell foam skin helps prevent dirt build-up Polyurethane foam enhances comfort, especially for long-term wear; 200 pairs of earplugs per refill pack Noise reduction rating 33; recommended industries: farming, chemical, construction, Law Enforcement, manufacturing, military, mining, municipal, oil & Gas, pharmaceutical, steel, metal, transportation