SparkPlugs Metal Detectable Foam Earplugs, Foam, Metal Detectable with Cord ORS NASCO Heat treated for greater durability on Heat treated for greater durability on the job Electronic coating for ultimate rust prevention Four sizes in each wrench saves time grease cartridge fun colors provide easy compliance checks Metal detectable for food processing applications The ball bearing and cord are in separate holes so that the ear plugs remain detectable even if the cord is removed The ear plugs are corded to prevent ear plug loss Their tapered shape fits easily in the ear canal and seals gently and snugly without pressure