3M Classic Metal Detectable Earplugs are made of PVC foam that offers comfort with low pressure and is an ergonomically, reliable choice in hearing protection. It is designed specially for food processing where earplugs are secured from contaminating products. The stainless steel ball bearing is encased in each earplug and the metal particles in the cord to eliminate rusting thus offering comfort to the hearing protector. Earplugs have a cylindrical shape that protects better than tapered plugs. The yellow color offers high visibility and the moisture resistant foam is flame retardant which is critical for storage. The noise reduction is rated at 33 dB and is corded for temporary storage around the neck. The earplugs come in a poly bag.