Spark Plugs� Detect earplugs have been specially developed for use in the food industry. The plugs and cord are metal detectable and are coloured blue for high visibility. Thanks to their specially developed foam formula, Spark Plugs� Detect earplugs offer the optimal combination of stability and softness. They are easy to roll and, upon insertion, expand to fill the ear canal at exactly the right time. There, they maintain a secure, sealed fit, without exerting pressure on the ear. Spark Plugs� Detect offer high noise protection of 32 dB (SNR).