Sold as 200/Box. Earplug. Metal-detectable Foam earplugs were specially developed for food processing and other industries where it is critical to keep earplugs from contaminating products and processes. Slow-recovery earplug Foam is flame-resistant and water-resistant. NRR 33 dB. Recognized by most metal-sensing systems, these earplugs feature an implanted stainless steel ball bearing in the plug and metal particles in the cord. Recommended for construction, general manufacturing, mining, oil and gas, transportation industry. Metal detectable cord. Poly bag keeps each pair of earplugs clean before use. Yellow. CSA Class AL.