3M ear classic earplugs offer excellent protection (NRR 29Db), have an easy-to-use cylinder shape, are made of soft, PVC foam and are moisture resistant. These useful earplugs are also Non-Allergic, non-flammable, and their bright yellow color assures compliance. 3M ear classic Uncorded earplugs provide all-day comfort. Refill bottle holds 500 earplugs for an outstanding value.