3M™ E-A-Rsoft™ SuperFit™ 30 Uncorded Earplugs, Poly Bag 312-1256 SuperFit earplugs are the only earplug model with a unique “fitting ring” to easily see when the earplug is correctly fitted. When no orange color is visible, the best fit is achieved. The red line provides a visible indication of correct fit. If the red line is visible then a correct fit has not been attained The tapered design of the earplug provides high protection levels Regular size fits most earcanals. Noise Reduction Rating (NRR)*: 33 dB. CSA Class AL.