SparkPlugs® also come in a metal detectable version which has a new metal detectable cord. The bright blue color is perfect for food processing applications. The enclosed metal ball bearing eliminates any exposed metal. 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. Features: 100% PVC-Free®; Highest independently tested NRR; Extra-soft, low-pressure foam for comfort and fit; Tapered shape for easy insertion and removal; Shaped to fit even very small ear canals; Non-irritating smooth surface; Officially licensed ear plugs of NASCAR®; Look for the exclusive coloured streaks and swirls as a symbol of Moldex quality.