2 Per Set NSN # 6515-00-442-4818 Noise Reduction Rating: 25 Decibels Super-soft Hypo-allergenic Silicone Offers Unsurpassed Comfort And Protection Three Ultra Thin Flanges Provide Exceptional Fit While Minimizing Pressure To The Inner Ear Insuring A High Level Of Acceptance Among Users May Be Reused Indefinitely Simply Wash In Warm Soapy Water Without Compromising Flexibility Comfort Or Protective Capabilities