Bright blue color and metal-detectable ball bearing help prevent product contamination. Patented, premolded, triple-flange design inserts easily. No rolling or sizing needed to get a comfortable, protective fit. Hypoallergenic polymer is washable and reusable. Poly bag keeps plugs clean and accessible for re-use. NRR 25dB. ANSI S3.19-1974; CSA Z94.2; CSA Class AL.